TY - JOUR A1 - Serbun, Pavel A1 - Bornmann, Benjamin A1 - Navitski, Aliaksandr A1 - Müller, Günter A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Stable field emission of single B-doped Si tips and linear current scaling of uniform tip arrays for integrated vacuum microelectronic devices JF - Journal of Vacuum Science & Technology B Nanotechnology and Microelectronics N2 - Advanced Si-based semiconductor technology is most suitable to fabricate uniform nanostructures as integrated field emitter arrays for novel vacuum electronic devices. In order to improve the field emission homogeneity and stability of p-type silicon tip arrays for pulsed sensor applications, the authors have systematically studied the influence of the fabrication parameters on the tip shape and on the specific operating conditions. Based on detailed design calculations of the field enhancement, they have fabricated two series of hexagonal arrays of B-doped Si-tips in a triangular arrangement. The first (second) type contains three (four) patches with different number of tips (1, 91, 547 and 1, 19, 1027, 4447 for the first and second type, respectively) of about 1 (2.5) μm height, ∼20 (20) nm apex radius, and 20 (10) μm pitch. The field emission properties of both individual tips and complete arrays were investigated with a field emission scanning microscope at a pressure of 10−9 mbar. The current plateau of these tips typically occurs at about 10 (3) nA and around 65 (25) V/μm field level. In this carrier saturation range, single tips provide the highest current stability (<5%) and optical current switching ratio (∼2.5). Fairly homogeneous emission of the tip arrays leads to an undershooting of the expected linear scaling of the mean plateau current as well as to a much improved current stability (<1%). Y1 - 2013 U6 - https://doi.org/10.1116/1.4765088 VL - 31 IS - 2 PB - AIP Publishing ER - TY - JOUR A1 - Schels, Andreas A1 - Edler, Simon A1 - Herdl, Florian A1 - Hansch, Walter A1 - Bachmann, Michael A1 - Ritter, Daniela A1 - Dudeck, Markus A1 - Duesberg, Felix A1 - Meyer, Manuel A1 - Pahlke, Andreas A1 - Hausladen, Matthias A1 - Buchner, Philipp A1 - Schreiner, Rupert T1 - In situ quantitative field emission imaging using a low-cost CMOS imaging sensor JF - Journal of Vacuum Science & Technology B N2 - Spatially resolved field emission measurements represent an important factor in further development of existing field emitter concepts. In this work, we present a novel approach that allows quantitative analysis of individual emission spots from integral current-voltage measurements using a low-cost and commercially available CMOS camera. By combining different exposure times to extrapolate oversaturated and underexposed pixels, a near congruence of integral current and image brightness is shown. The extrapolation also allows parallel investigation of all individual tips participating in the total current with currents ranging from a few nanoampere to one microampere per tip. The sensitivity, which is determined by the integral brightness-to-current ratio, remains unchanged within the measurement accuracy even after ten full measurement cycles. Using a point detection algorithm, the proportional current load of each individual tip of the field emitter array is analyzed and compared at different times during the initial measurement cycle. Together with the extracted I-V curves of single emission spots from the integral measurement, the results indicate the effect of premature burnout of particularly sharp tips during conditioning of the emitter. KW - ARRAYS KW - ELECTRON-EMISSION KW - EMITTERS KW - FakANK Y1 - 2022 U6 - https://doi.org/10.1116/6.0001551 VL - 40 IS - 1 PB - AIP Publishing ER - TY - JOUR A1 - Edler, Simon A1 - Schels, Andreas A1 - Herdl, Florian A1 - Hansch, Walter A1 - Bachmann, Michael A1 - Dudeck, Markus A1 - Duesberg, Felix A1 - Pahlke, Andreas A1 - Hausladen, Matthias A1 - Buchner Philipp, A1 - Schreiner, Rupert T1 - Origin of the current saturation level of p-doped silicon field emitters JF - Journal of Vacuum Science & Technology B N2 - Using p-type semiconductors for field emitters is one simple way to realize an integrated current limiter to improve the lifetime of the cathode. In this work, the origin of the current saturation of p-type silicon emitters is investigated in detail. Single emitters are electrically characterized and compared to simulation results. With a simulation model considering a high surface generation rate and elevated tip temperature, a good agreement to the measured data is found. This observation is supported further by alteration of the surface experimentally. Electrical measurements after different treatments in hydrofluoric acid as well as heated and subsequent operation at room temperature are well explained by the influence of surface generation. Furthermore, it is shown that the field penetration leads to a small voltage drop and a strong geometry-dependent reduction of the field enhancement factor. KW - EMISSION KW - GROWTH KW - NATIVE-OXIDE Y1 - 2022 U6 - https://doi.org/10.1116/6.0001554 VL - 40 IS - 1 PB - AIP Publishing ER - TY - CHAP A1 - Tschurtschenthaler, Karl A1 - Krenkel, Lars A1 - Schreiner, Rupert T1 - Mechano-optical micro pillar sensor for biofluidmechanic wall shear stress measurements T2 - 25th Congress of the European Society of Biomechanics (ESB), July 7-10, 2019, Vienna, Austria Y1 - 2019 UR - https://esbiomech.org/conference/archive/2019vienna/Contribution_608.pdf ER - TY - JOUR A1 - Bieker, Johannes A1 - Roustaie, Farough A1 - Schlaak, Helmut F. A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Lotz, Marcel A1 - Wilfert, Stefan T1 - Field emission characterization of in situ deposited gold nanocones with variable cone densities JF - Journal of Vacuum Science and Technology B N2 - For the fabrication of field emitter cathodes with metallic nanocones, an in situ fabrication technique based on electrodeposition in an ion track etched polymer template was used. Three samples with nanocones made of gold and different cone densities were deposited on a circular electrode with a diameter of 2.5 mm, using templates with pore density of 6 × 104, 4 × 105, and 1 × 106 cones/cm2. The cones had a height of 24 μm, a base diameter between 3 and 3.75 μm, and a tip diameter below 500 nm. Integral field emission measurements revealed onset fields of down to 3.1 V/μm and average field enhancement factors of up to 1240. For one sample, the maximum emission current from the cathode reached 142.2 μA at an applied voltage of 338 V between cathode and extraction grid, which had a distance of 50 μm. To investigate the stability of the field emission current, cumulative long-term measurements were performed for over 50 h. A stable emission current of (31.0 ± 1.3) μA at an average applied voltage of 290 V (E = 5.8 V/μm) was observed. For currents above 100 μA, a decrease of the current and therefore a degradation of the emitter structures occurred. Y1 - 2018 U6 - https://doi.org/10.1116/1.5009504 VL - 36 IS - 2 PB - AIP Publishing ER - TY - CHAP A1 - Dams, Florian A1 - Schreiner, Rupert T1 - A high thermal resistance MEMS-based Pirani vacuum sensor chip T2 - Smart sensors, actuators and MEMS VI : 24 - 26 April 2013, Grenoble, France / [part of SPIE microtechnologies] N2 - The performance of thermal conductivity vacuum gauges can be improved by a well-designed geometry. The lower measurement range limit is determined by the size of the active sensing area and the thermal conduction heat losses through the supporting structures. The upper measurement range is limited by the distance between the heated element and the cold reference plane. Silicon based MEMS-technology gives the possibility to fabricate both sensing structures with suitable areas out of low thermal conductive materials and narrow gaps in order to extend the measurement range in both directions. In this work we present a MEMS-process to fabricate high thermal resistance sensor structures. The rectangular sensitive areas are anchored by four beams and are structured out of low thermal conductive PECVD-siliconnitride films with 1 µm in thickness. The metallic heating structure is completely embedded in the SiN-layer. Both sensitive area and its support beams were released from the silicon bulk material by anisotropic underetching. In this way a free-supporting structure with a gap of 150 μm to the silicon substrate was formed. The influence of the filament geometry and temperature was systematically investigated to determine the properties of the chips as thermal conductivity vacuum gauges. The temperature of the sensitive area was held constant by a self-balancing bridge circuit and the heating power was measured by a Δ-Σ-ADC. The average solid state thermal conductivity is in the order of 106WK1. The measuring range of the most sensitive structures covers 8 orders of magnitude from 105 mbar to 1000mbar. Y1 - 2013 U6 - https://doi.org/10.1117/12.2017345 PB - SPIE CY - Bellingham, Wash. ER - TY - GEN A1 - Düsberg, Felix A1 - Bachmann, Michael A1 - Edler, Simon A1 - Pahlke, Andreas A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Schreiner, Rupert A1 - Bunert, Erik A1 - Wendt, Cornelius A1 - Zimmermann, Stefan T1 - Novel Non-Radiative Electron Source T2 - 43rd International Symposium of Capillary Chromatography & 16h GC x GC Symposium 2019 N2 - Recently a non-radioactive electron capture detector based on a thermionic electron emitter has been demonstrated [1]. Using field emitter arrays (FEAs) would yield non-radioactive portable low power devices with fast switching capability. By combining FEAs with a vacuum-sealed housing and an electron transparent membrane window, such electron sources can be operated in an ambient pressure environment. Y1 - 2019 ER - TY - CHAP A1 - Berndt, Dominik A1 - Lindner, Matthias A1 - Schreiner, Rupert A1 - Pipa, Andrei V. A1 - Hink, Rüdiger A1 - Brandenburg, Ronny A1 - Foest, Rüdiger A1 - Geils, Judith A1 - Sander, Aljoscha A1 - Hoffmann, Florian A1 - Matz, Daniel A1 - Baars, Albert A1 - Kesel, Antonia A1 - Max, Alexander A1 - Caspari, Ralf T1 - Realization of Multifunctional Surfaces Containing MEMS-based DBD Plasma Actuators and Biomimetic Structures for Flow Manipulation T2 - AIAA Aviation 2019 Forum, 2019, Dallas Y1 - 2019 U6 - https://doi.org/10.2514/6.2019-2999 PB - American Institute of Aeronautics and Astronautics, Inc ER - TY - CHAP A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Stable and low noise field emission from single p-type Si-tips T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - Single gated p-type Si-tips with two different tip radii were fabricated. An emission current of 2.40 μA was measured for the sharp-edged tip at a voltage of 170 V. In contrast, a stable and reproducible emission behavior was observed with an increased tip radius resulting in a pronounced saturation region between 90 V and 150 V, but merely an emission current of 0.55 μA at 150 V. More remarkable is the stable emission behavior with fluctuation of ± 4 % during a measurement period of 30 minutes. The integral emission current in a homogeneous tip array (16 emitters) showed nearly the same I-V characteristics compared to the single tip and is therefore, most dominated by only a stable single tip in the array. KW - field emission KW - p-type Si-tips KW - gate-electrode KW - emission stability KW - low current fluctuations Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520018 PB - IEEE ER - TY - CHAP A1 - Lindner, Matthias A1 - Berndt, Dominik A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Field emission assisted micro plasma discharges at vacuum and atmospheric pressures T2 - 31st International Vacuum Nanoelectronics Conference (IVNC), 2018, Kyoto, Japan N2 - Spatially confined non-equilibrium plasmas at vacuum and atmospheric pressure in the dimensions from a few microns to one millimeter are a promising approach to the generation and maintenance of stable glow discharges. The realization of these micro-discharges or micro-plasmas enable more accurate investigations in the field of micro plasma research. We report on field emission assisted micro plasmas excited by an alternating current with frequencies up to 1 kHz. Due to the field enhancement caused by an array of Si nano-tip structures the ignition voltage of stable plasma discharges can be reduced by 30%. Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520181 ER - TY - CHAP A1 - Berndt, Dominik A1 - Lindner, Matthias A1 - Tschurtschenthaler, Karl A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Miniaturized Plasma Actuator Flow Measurements by MEMS-Based Thermal Conductivity Sensors T2 - MDPI Proceedings of Eurosensors 2018, 9-12 September, Graz N2 - The gasflow created by a minaturized dielectric barrier discharge (DBD) plasma actuator is measured by a MEMS-based thermal conductivity gas sensor giving an indication of flow velocity and flow direction. The possiblity of several sensors in a small area gives a far better accuracy of local flow phenomena compared to conventional sensors. This is important for a better understanding of plasma- induced flow characteristics. KW - thermal conductivity sensors; plasma actuators; surface hotfilms; sensors for aerospace Y1 - 2018 U6 - https://doi.org/10.3390/proceedings2130939 VL - Vol.13 IS - 2 ER - TY - CHAP A1 - Edler, Simon A1 - Hansch, Walter A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Influence of adsorbates on the performance of a field emitter array in a high voltage triode setup T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - The influence of residual gas pressure on the characteristics of black-Silicon field emitter arrays in a high voltage triode setup is investigated. I-Vcharacteristics at different pressure levels show a decrease of emission current with rising pressure. This can be explained by an increase of the work function and charging of the emitter surface due to adsorbates. The initial characteristics can be restored by heating the FEA up to 110 °C during electron emission. This regeneration procedure enables an extension of the lifetime from about 20 h to 440 h at a residual gas pressure of 10 -5 mbar. KW - semiconductor field emission KW - field emitter array KW - silicon tips KW - emission current stability Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520214 PB - IEEE ER - TY - JOUR A1 - Berndt, Dominik A1 - Muggli, Josef A1 - Wittwer, Franz A1 - Langer, Christoph A1 - Heinrich, Stephan A1 - Knittel, Thorsten A1 - Schreiner, Rupert T1 - MEMS-based thermal conductivity sensor for hydrogen gas detection in automotive applications JF - Sensors and Actuators A: Physical N2 - Accurate detection of hydrogen gas in vehicle interiors is very important for the future of a fuel cell car. Since this type of gas is highly volatile and flammable, the measurement methods have to be very reliable and precise due to safety reasons. In this paper a thermal conductivity sensor for hydrogen gas detection is presented, exhibiting a lower detection limit of 2000 ppm hydrogen in laboratory air. The sensor element is realized by micro-fabrication techniques on silicon wafers. The heated filament is exposed by a selective wet etching process creating a micro-hotplate on a thin membrane. In order to minimize power consumption, the sensor is operated in pulsed mode. Hydrogen gas detection was carried out using a synthetic gas testbench. Measurements of hydrogen contents ranging from 0% to 4% with an increment of 0.5% were successfully performed for ambient gas temperatures between -15°C and 84°C. Including humidity, high moisture contents have the greatest influence on thermal conductivity. This was predicted in theoretical investigations and confirmed in experiments. For evaluation, both the change in resistance ΔR as well as the time constant τ were taken as sensor output. For both quantities, the previously established theoretical relationship with thermal conductivity could be confirmed. Y1 - 2020 U6 - https://doi.org/10.1016/j.sna.2019.111670 VL - 305 IS - April PB - Elsevier ER - TY - CHAP A1 - Silberbauer, Theodor A1 - Lindner, Matthias A1 - Schreiner, Rupert T1 - Charakterisierung der dielektrischen Barrierenentladung von Mikroplasmaaktuatoren in Abhängigkeit der Substratdicke T2 - Intelligente Systeme und ihre Komponenten: Forschung und industrielle Anwendung : Fachbeiträge 2. Symposium Elektronik und Systemintegration ESI 2020 Y1 - 2020 UR - https://nbn-resolving.org/urn:nbn:de:bvb:860-opus4-2130 N1 - Die Fachtagung, geplant für den 01. April 2020 an der Hochschule Landshut, wurde aufgrund der Corona-Pandemie abgesagt, die eingereichten Fachbeiträge im Tagungsband 2. Symposium Elektronik und Systemintegration ESI 2020: "Intelligente Systeme und ihre Komponenten: Forschung und industrielle Anwendung" veröffentlicht. Hrsg.: Artem Ivanov, Marc Bicker und Peter Patzelt. Hochschule Landshut, 2020, ISBN 978-3-9818439-4-1. SP - 64 EP - 72 CY - Landshut ER - TY - JOUR A1 - Krysztof, Michał A1 - Miera, Paweł A1 - Urbański, Paweł A1 - Grzebyk, Tomasz A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Integrated silicon electron source for high vacuum microelectromechanical system devices JF - Journal of Vacuum Science & Technology B N2 - The article presents the process of developing a silicon electron source designed for high-vacuum microelectromechanical system (HV MEMS) devices, i.e., MEMS electron microscope and MEMS x-ray source. Technological constraints and issues of such an electron source are explained. The transition from emitters made of carbon nanotubes to emitters made of pure silicon is described. Overall, the final electron source consists of a silicon tip emitter and a silicon gate electrode integrated on the same glass substrate. The source generates an electron beam without any carbon nanotube coverage. It generates a high and stable electron current and works after the final bonding process of an HV MEMS device. KW - Materials Chemistry KW - Electrical and Electronic Engineering KW - Surfaces, Coatings and Films KW - Process Chemistry and Technology KW - Instrumentation KW - Electronic, Optical and Magnetic Materials Y1 - 2024 U6 - https://doi.org/10.1116/6.0003385 SN - 2166-2746 VL - 42 IS - 2 PB - AIP Publishing ER - TY - JOUR A1 - Schreiner, Rupert A1 - Naegele, Peter A1 - Körbl, M. A1 - Groning, A. A1 - Gentner, Jean-Louis A1 - Schweizer, Heinz C. T1 - Monolithically integrated tunable laterally coupled distributed-feedback lasers JF - Photonics Technology Letters N2 - A new method for fabrication of tunable InGaAsP-InP single-mode lasers without epitaxial overgrowth is reported. These devices show the advantage of a considerably simplified fabrication process compared to conventional tunable laser types. The lasers comprise an active Bragg reflector integrated with an uncorrugated separately pumped gain region. By adjusting the current through the Bragg reflector, the wavelength can be tuned between 1590.8 and 1595.2 nm. KW - Tunable circuits and devices KW - Optical coupling KW - Laser tuning KW - Etching KW - Pump lasers KW - Laser feedback KW - Optical device fabrication KW - Distributed feedback devices KW - Gratings KW - Fiber lasers Y1 - 2001 U6 - https://doi.org/10.1109/68.969880 VL - 13 IS - 12 SP - 1277 EP - 1279 PB - IEEE ER - TY - CHAP A1 - Buchner, Philipp A1 - Kaiser, Alexander A1 - Hausladen, Matthias A1 - Bartl, Mathias A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Silicon Nanowire Field Emitters with Integrated Extraction Gates Using Benzocyclobutene as an Insulator T2 - 37th International Vacuum Nanoelectronics Conference (IVNC), 15-19 July 2024, Brno, Czech Republic N2 - We are continuously improving the performance of our field emission electron sources. In this work a geometrically optimized design of electron sources with silicon nanowire field emitters on pillars was fabricated. This new design increased the packing density of the emitters by using a hexagonal arrangement of the pillars and a pillar spacing of 40 µm. Benzocyclobutene was used as the insulator material for an integrated (Cr/Ni) extraction gate. A modified fabrication process for the field emitters further improved reproducibility and reliability. An emission current of about 0.4 mA was measured for 30 minutes at an extraction voltage of 250 V and an anode voltage of 500 V. Electron transmission through the gate reached almost 100%. Y1 - 2024 U6 - https://doi.org/10.1109/IVNC63480.2024.10652314 SP - 1 EP - 2 PB - IEEE ER - TY - JOUR A1 - Berndt, Dominik A1 - Muggli, Josef A1 - Heckel, Robert A1 - Rahiman, Mohd Fuad A1 - Lindner, Matthias A1 - Heinrich, Stephan A1 - Plöchinger, Heinz A1 - Schreiner, Rupert T1 - A Robust Miniaturized Gas Sensor for H₂ and CO₂ Detection Based on the 3ω Method JF - Sensors N2 - Gas concentration monitoring is essential in industrial or life science areas in order to address safety-relevant or process-related questions. Many of the sensors used in this context are based on the principle of thermal conductivity. The 3ω-method is a very accurate method to determine the thermal properties of materials. It has its origin in the thermal characterization of thin solid films. To date, there have been very few scientific investigations using this method to determine the thermal properties of gases and to apply it to gas measurement technology. In this article, we use two exemplary gases (H2 and CO2) for a systematical investigation of this method in the context of gas analysis. To perform our experiments, we use a robust, reliable sensing element that is already well established in vacuum measurement technology. This helix-shaped thin wire of tungsten exhibits high robustness against chemical and mechanical influences. Our setup features a compact measurement environment, where sensor operation and data acquisition are integrated into a single device. The experimental results show a good agreement with a simplified analytical model and FEM simulations. The sensor exhibits a lower detection limit of 0.62% in the case of CO2, and only 0.062% in case the of H2 at an excitation frequency of 1 Hz. This is one of the lowest values reported in literature for thermal conductivity H2 sensors. KW - 3ω-method KW - CO2 sensor KW - H2 sensor KW - thermal gas sensor Y1 - 2022 U6 - https://doi.org/10.3390/s22020485 N1 - Corresponding author: Dominik J. Berndt VL - 22 IS - 2 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Schreiner, Rupert A1 - Körbl, M. A1 - Gräbeldinger, H. A1 - Gentner, Jean-Louis A1 - Schweizer, H. T1 - Laterally gain-coupled 1.57 [micro sign]m DFB lasers with chromium surface grating and self-aligned Ti/Pt/Au ohmic contact JF - Electronics Letters N2 - A simple method for fabricating gain coupled DFB lasers with lateral surface chromium Bragg gratings and self-aligned low capacitance ohmic contacts is reported. These InGaAsP/InP lasers show monomode emission with a sidemode suppression ratio of 40 dB. For 243 µm long devices a continuous wave threshold current of 17 mA was measured at room temperature. KW - Bragg gratings KW - platinum KW - chromium KW - ohmic contacts KW - titanium KW - distributed feedback lasers KW - gold Y1 - 2000 U6 - https://doi.org/10.1049/el:20000500 SN - 0013-5194 VL - 36 IS - 7 SP - 636 EP - 637 PB - The Institution of Engineering and Technology, IET ER - TY - JOUR A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Dams, Florian T1 - Compact and Energy-Efficient Field Emission Cathodes for Sensor Applications JF - Advanced Materials Research N2 - We report on miniaturized silicon field emitter arrays for the application in compact and energy-saving vacuum-microelectronic devices, e.g. sensors or x-ray tubes. Since standard silicon semiconductor technology has been used for the fabrication, they may be easily integrated with other silicon based circuits and devices on the same chip. The silicon tip geometry and the operating conditions were optimized in order to obtain highly uniform and stable electron field emission from large area cathode arrays. A series of uniform hexagonal tip arrays containing each 547 tips were fabricated and characterized. The electron emission properties of both individual tips as well as of complete emitter arrays were investigated. A saturation level in the voltage-current characteristics was found, which can be explained by the limitation of the supply of electrons due to the p-type silicon wafer material. When operating the arrays in the current saturation regime at an emission current of ~ 1 nA per tip, a highly stable and low noise emission can be observed. KW - field emission KW - Si-Tip Cathodes KW - Vacuum Sensors Y1 - 2014 U6 - https://doi.org/10.4028/www.scientific.net/amr.1024.372 VL - 1024 SP - 372 EP - 375 PB - Scientific.net ER - TY - CHAP A1 - Hausladen, Matthias A1 - Bomke, Vitali A1 - Buchner, Philipp A1 - Bachmann, Michael A1 - Knapek, Alexandr A1 - Schreiner, Rupert T1 - Influence of Geometrical Arrangements of Si Tip Arrays Fabricated by Laser Micromachining on their Emission Behaviour T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 7/5/2021 - 7/9/2021, Lyon, France N2 - ensely packed emitters on a field emission array lead typically to mutual shielding. Taking biology as a role model for geometric arrangements could be a way to reduce this effect. For comparison, two electron sources, one with a spiral and a second with conventional rectangular (orthogonal) arranged emitters, were fabricated and investigated. Emission currents of 6 µA in the spiral ordered array and 120 µA in the rectangular array were reached with an extraction voltage of 400 V. From a mid-term measurement over 1 h a current stability of ±8.8 % (spiral) respectively ±5.7 % (rectangular) with a mean degradation of -3.0 µA/h (spiral) and -0.12 µA/h (rectangular) could be observed. KW - aperture field KW - emission grid KW - Fabrication KW - laser micromachining KW - parastichy tip arrangements KW - silicon field emission KW - Stability analysis KW - Spirals KW - Field emitter array KW - Voltage measurement Y1 - 2021 SN - 978-1-6654-2589-6 U6 - https://doi.org/10.1109/IVNC52431.2021.9600717 SN - 2380-6311 PB - IEEE CY - Piscataway, N.J. ER - TY - CHAP A1 - Buchner, Philipp A1 - Bomke, Vitali A1 - Hausladen, Matthias A1 - Edler, Simon A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Investigation on the Emission Behaviour of p-doped Silicon Field Emission Arrays with Individually Controllable Single Tips T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 7/5/2021 - 7/9/2021, Lyon, France N2 - Four individually controllable emission tips consisting of <111> p-Type silicon, were structured on a glass substrate by laser ablation. A matching extraction grid was manufactured in the same manner and aligned with the emitters. The resulting samples were characterized in ultra-high vacuum. As expected, the individual currents show a strong saturation and in the saturation region a considerably lower current fluctuation than n-type silicon due to charge carrier depletion. The individual tips behave completely independent behaviour from each other and the overall emission can be deduced from the sum of the currents through the individual tips. Y1 - 2021 SN - 978-1-6654-2589-6 U6 - https://doi.org/10.1109/IVNC52431.2021.9600756 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Hecht, Fabian A1 - Bauereiβ, Florian A1 - Sellmair, Josef A1 - Buchner, Philipp A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Electron Beam Induced Growth of Carbon Nanotips on Tungsten and Silicon Fieldemitters T2 - 2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA N2 - In our experiments we grew electron emitting carbon nanostructures on tungsten tips. Subsequently, we transferred the growth process to pre-structured phosphorus-doped n-type silicon and obtained emitting carbon nanostructures directly grown on silicon. After growth of the nanostructures, the silicon field emitters showed increased emission currents of 76 nA at 1.1 kV (compared to 6 nA under the same conditions before growth). KW - Behavioral sciences KW - Nanostructures KW - Silicon KW - Carbon dioxide KW - Current measurement KW - Electron beams KW - Tungsten Y1 - 2023 SN - 979-8-3503-0143-4 U6 - https://doi.org/10.1109/IVNC57695.2023.10188960 SP - 160 EP - 162 PB - IEEE ER - TY - CHAP A1 - Allaham, Mohammad M. A1 - Buchner, Philipp A1 - Schreiner, Rupert A1 - Knápek, Alexandr T1 - Testing the performance of Murphy-Good plots when applied to current-voltage characteristics of Si field electron emission tips T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France N2 - Murphy-Good plots are the most recent type of the analysis methods in the field electron emission theory, this type of plots has several useful characteristics such as: having the very-nearly straight line to represent the current-voltage characteristics and the absence of the correction factors in the mathematical procedure of the analysis process. In this study, n-type <111> and <100> Si chips containing four individual emitters are used as base emitters and mounted in a diode configuration field emission setup where the experiments are operated in an ultra-high vacuum ( 10-7 Pa). Each chip has four individual controllable emitters with 5 µm distance between the Si tips and the same material grid. Laser micromachining and subsequent wet chemical etching technique is used to structure and polish the tips. Murphy-Good plots are used to study the behavior of the Si individual tips and compare the results with the array current by extracting the field emission characterization parameters of the emitters. KW - characterization parameter KW - Current-voltage characteristics KW - electron emission KW - electron source KW - Limiting KW - Micromachining KW - Murphy-Good plot KW - n-type Si chip KW - RESISTANCE KW - safety KW - silicon Y1 - 2021 U6 - https://doi.org/10.1109/IVNC52431.2021.9600690 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Zheng, Jihong A1 - Fuhrmann, Thomas A1 - Xu, Boqing A1 - Schreiner, Rupert A1 - Jia, Hongzhi A1 - Zhang, Wei A1 - Wang, Ning A1 - Seebauer, Gudrun A1 - Zhu, Jiyan T1 - Curriculum design and German student exchange for Sino-German Bachelor program majored in optoelectronics engineering T2 - 14th Conference on Education and Training in Optics and Photonics (ETOP 2017), 29-31.05.2017, Hangzhou, China, 29-31.05.2017 N2 - Different higher education backgrounds in China and Germany led to challenges in the curriculum design at the beginning of our cooperative bachelor program in Optoelectronics Engineering. We see challenges in different subject requirements from both sides and in the German language requirements for Chinese students. The curriculum was optimized according to the AS IIN criteria, which makes it acceptable and und erstandable by both countries. German students are integrated into the Chinese class and get the sa me lectures like their Chinese colleagues. Intercultural and curriculum challenges are successfully solved. The results are summarized to provide an example for other similar international programs. KW - cooperative bachelor program KW - optoelectronics KW - microsystems KW - student exchange Y1 - 2017 U6 - https://doi.org/10.1117/12.2269574 PB - SPIE ER - TY - CHAP A1 - Bieker, Johannes A1 - Roustaie, Farough A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Schlaak, Helmut F. T1 - Innovatives Verfahren zur Herstellung und Integration metallischer Nanokonen für die Feldemission T2 - MikroSystemTechnik Kongress 2017 : MEMS, Mikroelektronik, Systeme 23.-25. Oktober 2017 in München N2 - In den letzten Jahren wurde am Institut für Elektromechanische Konstruktionen die Fabrikation und Integration von metallischen Nanodrähten und Nanokonen mittels Template-basierter Abscheidung erforscht. Diese Variante der in-situ Abscheidung von metallischen Nanostrukturen bietet eine Vielzahl von Anwendungsmöglichkeiten. Im Rahmen dieses Beitrags werden das Herstellungsverfahren zur Herstellung metallischer Nanokonen vorgestellt. Dies beinhaltet sowohl die Templatepräparation mittels asymmetrischen Ätzens als auch die anschließende Integration mittels galvanischer Abscheidung. Eine Anwendung der metallischen Nanokonen stellt die Verwendung als Feldemitter in der Vakuumelektronik dar. Es werden erste Messungen der Langzeitstabilität des Feldemissionsstromes der metallischen Konen präsentiert. N2 - Recently the fabrication and integration of metallic nanowires and nanocones based on ion-track etched templates has been in the focus of research at the Institute for Electromechanical Design at the TU Darmstadt. Using the method for the in-situ deposition various applications are feasible. In this paper we present the fabrication method for in-situ deposition of metallic nanocones, including the preparation of the polymer templates based on asymmetric etching and the process description for integration via electrodeposition. Giving one example for an application, the metallic nanocones can be used as field emitters in vacuum electronics. The field emission properties will be presented briefly. T2 - Innovative fabrication method for in-situ deposition of metallic nanocones for field emission KW - Ätzen KW - Feldemission KW - galvanische Abscheidung KW - Herstellverfahren KW - Langzeitstabilität KW - Nanodraht KW - Nanostruktur KW - Polymer KW - Prozessbeschreibung KW - Vakuum Y1 - 2017 SN - 978-3-8007-4491-6 IS - CD-ROM SP - 797 EP - 800 PB - VDE-Verlag CY - München ER - TY - CHAP A1 - Rahiman, Mohd Fuad A1 - Berndt, Dominik A1 - Schreiner, Rupert T1 - Micro-wire Pirani with temperature-stabilized Environment T2 - 3. Symposium Elektronik und Systemintegration ESI 2022: 06. April 2022, Hochschule Landshut Y1 - 2022 SN - 978-3-9818439-7-2 SP - 52 EP - 59 ER - TY - GEN A1 - Schreiner, Rupert T1 - Miniaturized sensor and actuator elements based on the heat transport in gases or the ionization of gas particles T2 - 16th International Conference on Optical and Electronic Sensors, COE'2020, 29 March - 2 April 2020, Krakow, Poland (online) Y1 - 2021 ER - TY - CHAP A1 - Kleshch, Victor I. A1 - Serbun, Pavel A1 - Orekhov, Anton A1 - Lützenkirchen-Hecht, Dirk A1 - Obraztsov, Alexander N. A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Lutzenkirchen-Hecht, Dirk T1 - Field emission properties of p-type silicon tips decorated with tungsten nanoparticles T2 - 2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany N2 - An array of conical-shaped p-type silicon tips was fabricated by using reactive ion etching and sharpening oxidation. The apex of each tip was decorated by a tungsten hemispherical nanoparticle. Field emission properties of the tips were measured by a tungsten-needle anode positioned above the tip apex. Tips decorated with tungsten nanoparticles demonstrated a smaller saturation region in current-voltage characteristics compared to the pristine tips. An emission activation process, which consisted in sudden current increase at certain value of applied voltage, was observed for the decorated silicon tips. This behavior was explained by the formation of vertical protrusions extending from the metal particles revealed by scanning electron microscopy after field emission experiments. KW - Current measurement KW - field emission KW - Ions KW - Iron KW - metal nanoparticles KW - nanoparticles KW - p-type silicon KW - Scanning electron microscopy KW - silicon KW - Tungsten Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051580 SP - 138 EP - 139 PB - IEEE ER - TY - CHAP A1 - Wick, Michael A1 - Lindner, Gerhard A1 - Zimmer, Katja A1 - Schreiner, Rupert A1 - Fuhrmann, Thomas A1 - Seebauer, Gudrun A1 - Xu, Boqing A1 - Zheng, Jihong A1 - Wang, Ning ED - Liu, Xu ED - Zhang, Xi-Cheng T1 - German-Chinese cooperative Bachelor in engineering physics/optoelectronics T2 - 14th Conference on Education and Training in Optics and Photonics: ETOP 2017; Hangzhou, China 29.05.2017 - 31.05.2017 N2 - The University of Shanghai for Science and Technology (USST), the Coburg University of Applied Sciences and Arts (CUASA) and the OTH Regensburg, University of Applied Sciences (OTHR) established an English taught international cooperative bachelor program in the area of Engineering Physics/Optoelectronics. Students from China study their first four semesters at USST. They continue their studies in Germany for the last three semesters, including an internship and a bachelor thesis, graduating with a Chinese and a German bachelor degree. Students from Germany study their third and fourth semester at USST to gain international experience. While the first cohort of Chinese students is currently in Germany, the second cohort of German students is in Shanghai. Up to now the feedback regarding this study program is completely positive, thus it is planned to develop it further. Y1 - 2017 SN - 9781510613812 U6 - https://doi.org/10.1117/12.2269943 PB - SPIE ER - TY - CHAP A1 - Knapp, Wolfram A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Lindner, Matthias A1 - Schreiner, Rupert T1 - Investigations of the transition from field electron emission to stable plasma discharge in a micro electron source at vacuum pressure T2 - 2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany N2 - We report on the transition from field electron emission to plasma discharges. During an experiment with a miniaturized field emission electron source a plasma discharge accompanied by a luminous effect was observed. A novel graphical evaluation method was used to interpret and to compare the observed phenomenon. KW - CATHODES KW - Discharges (electric) KW - electron source KW - electron sources KW - Fault location KW - field emission KW - field emission measurement KW - glow discharge KW - Glow discharges KW - micro arc KW - plasma discharge KW - Plasmas KW - Si-tip cathode Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051594 SP - 166 EP - 167 PB - IEEE ER - TY - JOUR A1 - Schreiner, Rupert A1 - Schweizer, Heinz C. T1 - High-frequency operation of 1.57-μm laterally coupled distributed feedback lasers with self-aligned ohmic contacts and nickel surface gratings JF - IEEE Journal of Selected Topics in Quantum Electronics N2 - Laterally coupled distributed feedback lasers with self-aligned ohmic contacts show the advantage of a considerably simplified fabrication process. These lasers exhibit superior spectral properties with full benefit from the gain coupling mechanism. Side-mode suppression ratios up to 55- and 3-dB bandwidths beyond 15 GHz were obtained for these devices. KW - Distributed feedback devices KW - Optical coupling KW - Laser feedback KW - Ohmic contacts KW - Nickel KW - Surface emitting lasers KW - Gratings KW - Optical device fabrication KW - Mechanical factors KW - Bandwidth Y1 - 2003 U6 - https://doi.org/10.1109/JSTQE.2003.819469 VL - 9 IS - 5 SP - 1179 EP - 1182 PB - IEEE ER - TY - JOUR A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Influencing factors on the sensitivity of MEMS-based thermal conductivity vacuum gauges JF - Journal of vacuum science & technology A N2 - The measurement range of thermal conductivity vacuum gauges is mainly influenced by the sensitivity of the sensing element to variations in pressure. An enhanced definition of sensitivity shows its theoretical dependence on the geometric measures of the sensor element at the whole pressure range. This value gives the possibility of direct comparison between different types of sensor structures without the influence of the operating conditions. To study the influencing factors, sensor chips with heated surfaces in the order of some tens of mm 2 were realized by microelectromechanical systems-based fabrication techniques. By a silicon-glass hybrid process two cold planes were formed in a distance of 150 mu m above and below the heated element. The thermal conductance of devices with different geometric measures was determined in constant temperature operating mode by usage of embedded measurement equipment. In this configuration the sensor signals were sensitive to pressure in a region from 10(-5) mbar. The sensitivity was extracted by a fit of the theoretical model to the measurement data and showed the predicted dependencies on the geometric measures. (C) 2014 American Vacuum Society. KW - Pirani Gauge KW - Pressure Sensor Y1 - 2014 U6 - https://doi.org/10.1116/1.4867486 VL - 32 IS - 3 PB - AVS ER - TY - JOUR A1 - Dams, Florian A1 - Navitski, Aliaksandr A1 - Prommesberger, Christian A1 - Serbun, Pavel A1 - Langer, Christoph A1 - Müller, Günter A1 - Schreiner, Rupert T1 - Homogeneous Field Emission Cathodes With Precisely Adjustable Geometry Fabricated by Silicon Technology JF - IEEE Transactions on Electron Devices N2 - Silicon-based cathodes with precisely aligned field emitter arrays of sharp tips applicable for miniaturized electron sources were successfully fabricated and characterized. This was made possible by an improved fabrication process using wet thermal oxidation, wet etching, and reactive-ion etching steps with adjustable anisotropy. As substrate materials, both p-doped silicon and n-doped silicon were used. The cathode chips contain about 3 × 10 5 Si tips/cm 2 in a triangular array with tip heights of 2.5 μm, tip radii of less than 30 nm, and spacing of 20 μm. Well-aligned field emission (FE) and excellent homogeneity from all tips (i.e., 100% efficiency) and maximum stable currents of typically 0.1 μA (0.6 μA) for p (n)-type Si were reproducibly achieved. The current-voltage characteristics of the p-Si tips exhibit the expected saturation at around 10 nA with around ten times better current stability, whereas the n-Si tips show the usual Fowler-Nordheim behavior. Additional coating of the Si tips with 5-nm Cr and 10-nm Au layers resulted in improved stability and at least five times higher average FE current limits (about 3 μA) at about 30% higher operation voltage. KW - cathodes KW - electron field emission KW - elemental semiconductors KW - Field emission (FE) cathodes KW - field emitter array (FEA) KW - miniaturized electron sources KW - oxidation KW - silicon KW - silicon tips KW - sputter etching Y1 - 2012 U6 - https://doi.org/10.1109/TED.2012.2206598 SN - 0018-9383 SN - 1557-9646 VL - 59 IS - 10 SP - 2832 EP - 2837 PB - IEEE ER - TY - JOUR A1 - Tan, Pi Lin A1 - Yeap, Guan Yeow A1 - Chow, Wen Shyang A1 - Schreiner, Rupert A1 - Cheong, Kuan Yew T1 - Effect of Thickness of Porphyrin on Electrical Properties of Organic Devices JF - Advanced Materials Research (AMR) N2 - The study on electrical properties for both 2,3,7,8,12,13,17,18-octaethyl-21,23H-porphine Cu (II) (Cu-porphyrin) and 2,3,7,8,12,13,17,18-octaethyl-21,23H-porphine (porphyrin) thin film, which were fabricated using spin coating method was conducted. Porphyrins were diluted with chloroform of various concentrations (0.05 mg/ml, 0.1 mg/ml, 0.5 mg/ml, 2.0 mg/ml and 3.0 mg/ml). The solution was spin coated on top of glass substrates. A layer of aluminum was evaporated on top of the organic thin film through thermal evaporation and shadow mask was placed on top of the organic thin film where two electrodes with a gap of 50 μm were formed. Surface morphology of the organic thin film was observed by scanning electron microscope (SEM) and profilometer. Different concentrations of organic solutions greatly affected the molecular packing and arrangement order of the organic thin film and thickness of the organic layer and eventually affected electrical properties of the devices. KW - Porphyrin KW - Electrical Properties KW - Spin Coating Y1 - 2014 U6 - https://doi.org/10.4028/www.scientific.net/AMR.1024.381 SN - 1662-8985 SN - 1022-6680 VL - 1024 SP - 381 EP - 384 PB - Trans Tech Publications Ltd. CY - Baech ER - TY - JOUR A1 - Langer, Christoph A1 - Berndt, Dominik A1 - Schreiner, Rupert T1 - Sensitivity of thermal conductivity vacuum gauges for constant current and constant temperature operation JF - Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics N2 - To optimize the measurement range of thermal conductivity vacuum gauges, an expression for the sensitivity is required that takes into account all geometrical, material-specific, and operating parameters. Therefore, equations of the sensor output signal as a function of the pressure for the constant current and the constant temperature mode have been developed analytically. Based on these equations, the sensitivity of the vacuum gauge and its influencing parameters was investigated and discussed. For comparable conditions, the constant temperature operation shows a significantly higher sensitivity for high pressures, while the constant current operation shows higher sensitivity at low pressures. The sensitivity in both the constant current and the constant temperature mode depends on the ratio of the filament surface area and the parasitic thermal conductance. In addition, for the constant current operation, the sensitivity also depends on the current value and the temperature coefficient of the filament resistor. For the constant temperature operation, the sensitivity additionally depends on the distance of the filament and the reference plane. However, to extend the measurement range of a thermal conductivity vacuum gauge toward low pressures, a reduction of the parasitic thermal conductance is mandatory for both the constant current and the constant temperature mode. Y1 - 2022 U6 - https://doi.org/10.1116/6.0001964 VL - 40 IS - 5 PB - AIP Publishing ER - TY - CHAP A1 - Dams, Florian A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Fabrication process of silicon-tip-arrays for field emission applications T2 - 24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Historische Stadthalle Wuppertal, Germany N2 - A micromachined process to assemble homogeneous and reproducible tip arrays for field emission applications is developed and characterized. As substrate material p- as well as n-doped silicon is used. Lateral position of the tips is defined by structuring silicon dioxide to discs in a photolithographic process. Vertical structure of the tips is defined by a combination of RIE dry etching with controlled anisotropy and thermally oxidization of silicon in order to sharpen the tips. Hence field emitter arrays (FEAs) can be assembled both as bare and coated cathodes. To assemble field emission diodes, this fabrication process allows placing a metal anode in a micrometer order distance to the tips by a self-aligning procedure. The anode is placed in an evaporation process whereupon sharpening oxide is used as isolator between anode and cathode. Electrical characterization of the cathodes showed very good homogeneity, well alignment and stability over time of emission current from all tips (i.e. 100% efficiency). KW - elemental semiconductors KW - etching KW - fabrication KW - field emission KW - field emitter arrays KW - homogeneity KW - micromachining KW - oxidation, silicon KW - silicon technology Y1 - 2011 UR - https://ieeexplore.ieee.org/document/6004556?arnumber=6004556 SN - 978-3-00-035081-8 SN - 978-1-4577-1243-2 SN - 2380-6311 SN - 2164-2370 SP - 49 EP - 50 PB - IEEE ER - TY - CHAP A1 - Schreiner, Rupert A1 - Mulot, M. A1 - Wiedmann, Jörg A1 - Coenning, W. A1 - Porsche, J. A1 - Gentner, Jean-Louis A1 - Berroth, Manfred A1 - Scholz, Ferdinand A1 - Schwizer, H. T1 - Dynamic measurements on narrow linewidth complex coupled 1.55 μm DFB lasers with gain and index grating in antiphase T2 - Conference Proceedings. Eleventh International Conference on Indium Phosphide and Related Materials (IPRM'99), 16-20 May 1999, Davos, Switzerland N2 - We report on dynamic measurements on antiphase complex coupled 1.55 /spl mu/m DFB lasers. The antiphase complex coupling mechanism is realized by periodically etching the active layer and quarternary InGaAsP overgrowth. This new fabrication approach results in very narrow linewidths measured on devices with rather short resonator lengths. The minimum linewidth for a 375 /spl mu/m long ridge waveguide laser was only 250 kHz at an optical output power of 4 mW. The RC-limited 3dB-bandwidth for those devices was /spl sim/6 GHz. Using circuit model corrections, the intrinsic bandwidth limitation of those lasers was found to be 17.4 GHz. KW - Waveguide lasers KW - Optical resonators KW - Optical waveguides KW - Laser modes KW - Optical coupling KW - Etching KW - Optical device fabrication KW - Length measurement KW - Power lasers KW - Power generation Y1 - 1999 SN - 0-7803-5562-8 U6 - https://doi.org/10.1109/ICIPRM.1999.773626 SP - 25 EP - 28 PB - IEEE CY - Piscataway ER - TY - CHAP A1 - Schreiner, Rupert A1 - Naegele, Peter A1 - Koerbl, Michael A1 - Groening, Albert A1 - Gentner, Jean-Louis A1 - Schweizer, Heinz C. ED - Mirin, Richard P. ED - Menoni, Carmen S. T1 - Monolithically integrated tunable laterally-coupled distributed feedback lasers with self-aligned Ti/Pt/Au ohmic contacts T2 - Proceedings Volume 4871, Semiconductor Lasers and Optical Amplifiers for Lightwave Communication SystemsSemiconductor Lasers and Optical Amplifiers for Lightwave Communication Systems N2 - We present a new method for fabrication of tunable InGaAsP-InP single mode lasers without epitaxial overgrowth. These devices show the advantage of a considerably simplified fabrication process compared to conventional tunable laser types. The lasers comprise an active Bragg reflector integrated with an uncorrugated separately pumped gain region. To overcome the extensive and expensive overgrowth step we realized a surface grating on both sides of the ridge mesa, which provides DFB operation. By adjusting the current through the Bragg reflector, the wavelength can be tuned between 1590.8 nm and 1595.2 nm. A maximum of 11 wavelength channels with an average spacing of ~0.5 nm and a constant optical output power of ~0.5 mW are addressable. Y1 - 2002 U6 - https://doi.org/10.1117/12.457281 PB - SPIE ER - TY - JOUR A1 - Cheong, Kuan Yew A1 - Aw, Kean A1 - Karimov, Khasan S. A1 - Zhao, Feng A1 - Mahroof-Tahir, Mohammad A1 - Schreiner, Rupert T1 - Advances in Smart Materials and Applications JF - Advances in Materials Science and Engineering N2 - This is one of a series of special issues published in Advances in Materials Science and Engineering, focusing on the latest advances of smart materials and their applications. Evolution of engineering materials is strongly depending on the growing transformation of complexity in engineering products. New materials being designed are required to provide specific properties and demonstrate certain functional characteristics by manipulating their dimension, chemistry, and structure through various advanced technologies. Therefore, “smartness” of a material has become the topic of interest. Properties of smart materials may change accordingly to the applied external stimuli. Under the direction of the editorial team, we showcase advances of organic and inorganic based smart materials and their applications in areas of specific interest such as energy, environment, and health. A total of 9 articles are published in this special issue. Six articles are focused on production, synthesis, and optimization of smart materials; and the remaining are dedicated to application of smart materials. Y1 - 2014 U6 - https://doi.org/10.1155/2014/517342 PB - Hindawi ER - TY - CHAP A1 - Saravanan, Brem Kumar A1 - Gerlach, Philipp A1 - Peschke, Martin A1 - Knoedl, Thomas A1 - Schreiner, Rupert A1 - Hanke, Christian A1 - Stegmueller, Bernhard T1 - Integrated DFB laser electro-absorption modulator based on identical MQW-double stack active layer for high-speed modulation beyond 10 GBIT/S T2 - 16th IPRM. 2004 International Conference on Indium Phosphide and Related Materials, 31 May - 04 June 2004, Kagoshima, Japan N2 - Integrated DFBLD-EAM-SOA devices utilizing an identical MQW active region have been realized in the AlGaInAs/InP material system. A fiber-coupled optical power of >6 mW with a 10 dB static extinction, 44 dB SMSR single-mode spectrum and a 3 dBe cutoff frequency of 25 GHz was measured. KW - Quantum well devices KW - Fiber lasers KW - Indium phosphide KW - Optical materials KW - Optical fiber devices KW - High speed optical techniques KW - Optical modulation KW - Cutoff frequency KW - Power measurement KW - Frequency measurement Y1 - 2004 SN - 0-7803-8595-0 U6 - https://doi.org/10.1109/ICIPRM.2004.1442656 SP - 236 EP - 238 PB - IEEE ER - TY - JOUR A1 - Zahner, Th A1 - Schreiner, Rupert A1 - Stierstorfer, R. A1 - Kus, O. A1 - Li, S. T. A1 - Roessler, R. A1 - Pedarnig, J. D. A1 - Bäuerle, D. A1 - Lengfellner, H. T1 - Off-diagonal Seebeck effect and anisotropic thermopower in Bi2Sr2CaCu2O8 thin films JF - Europhysics Letters N2 - The anisotropy ΔS of the thermopower in thin films of the high-Tc superconductor Bi2Sr2CaCu2O8 is investigated using off–c-axis epitaxial film growth and the off-diagonal Seebeck effect. The measurements represent a new method for the investigation of anisotropic transport properties in solids, taking advantage of the availability of oriented grown crystalline thin films instead of using bulk crystals. First results for the temperature dependence ΔS(T) in Bi2Sr2CaCu2O8 thin films are presented and described within a two-band model. Subjecting the films to heat treatments in different gases at relatively low temperatures, ΔS could reversibly be changed in a wide range. Y1 - 1997 U6 - https://doi.org/10.1209/epl/i1997-00521-4 VL - 40 IS - 6 SP - 673 EP - 678 PB - IOP Sciences ER - TY - CHAP A1 - Knodl, Thomas A1 - Hanke, Christian A1 - Saravanan, Brem Kumar A1 - Peschke, Martin A1 - Schreiner, Rupert A1 - Stegmuller, Bernhard ED - Righini, Giancarlo C. ED - Honkanen, Seppo T1 - Integrated 1.3-μm InGaAlAs-InP laser-modulator with double-stack MQW layer structure T2 - Proceedings Volume 5451, Integrated Optics and Photonic Integrated Circuits N2 - We present first experimental results of the successful transfer of our monolithic integrated double-stack multi quantum well laser-modulator approach from the traditional InGaAsP/InP to the more promising InGaAlAs/InP material system. In continuous wave operation at room temperature, the devices achieved threshold currents of <21 mA, fiber coupled optical power levels up to 570 μW and static extinction ratios in the range of 15 dB/V. The measured small-signal modulation bandwidth of about 10 GHz is capacitance limited due to a conservative device layout. Y1 - 2004 U6 - https://doi.org/10.1117/12.544610 PB - SPIE ER - TY - CHAP A1 - Schreiner, Rupert A1 - Grabeldinger, H. A1 - Wiedmann, J. A1 - Wunstel, K. A1 - Porsche, J. A1 - Scholz, Ferdinand A1 - Schweizer, H. T1 - Complex coupled 1.55 mu m tunable super-grating DFB lasers and photonic filters T2 - Compound semiconductors 1999 : proceedings of the Twenty-Sixth International Symposium on Compound Semiconductors held in Berlin, Germany, 22 - 26 August 1999 N2 - We report on the investigation and realization of photonic filters based on the combination of fractional compositions of a few basic grating periods. Using a minimum set of two basic periods Lambda(1) and Lambda(2) we demonstrate comb-like few mode photonic band gap structures with arbitrary numbers of bands and frequency spacing between the bands. Optically integrated filters of different comb periods result in switchable wavelength filters for channel selection in WDM applications. Y1 - 2000 UR - https://www.researchgate.net/publication/296464112_Complex_coupled_155_mu_m_tunable_super-grating_DFB_lasers_and_photonic_filters SN - 0-7503-0704-8 PB - Inst. of Physics Publ. CY - Bristol [u.a.] ER - TY - CHAP A1 - Schreiner, Rupert A1 - Schweizer, Heinz C. T1 - High frequency operation of 1.57 μm laterally gain coupled DFB lasers with self aligned ohmic contacts and nickel surface gratings T2 - IEEE 18th International Semiconductor Laser Conference; 29 Sept.-3 Oct. 2002, Garmisch, Germany N2 - Laterally coupled DFB lasers with self-aligned ohmic contacts show the advantage of a, considerably simplified fabrication process. Side-mode-suppresion-ratios up to 55 dB and 3 dB-bandwidths beyond 15 GHz were obtained for these devices. KW - Frequency KW - Optical coupling KW - Distributed feedback devices KW - Etching KW - Laser theory KW - Laser modes KW - Nickel KW - Laser feedback KW - Waveguide lasers KW - Laser noise Y1 - 2002 SN - 0-7803-7598-X U6 - https://doi.org/10.1109/ISLC.2002.1041099 SP - 21 EP - 22 PB - IEEE ER - TY - CHAP A1 - Podstránský, Jáchym A1 - Hausladen, Matthias A1 - Zlámal, Jakub A1 - Knápek, Alexandr A1 - Schreiner, Rupert T1 - Single Column Multiple Electron Beam Imaging from N-Type Silicon T2 - 37th International Vacuum Nanoelectronics Conference (IVNC), 15-19 July 2024, Brno, Czech Republic N2 - This work is aimed at measuring the electron emission from multiple cathodes formed by n-doped silicon and imaging the electron beams focused by an einzel lens on a CMOS camera. The experimental results are compared with computer simulation to understand the electron emission from the semiconductor cathode and the observed imaging imperfections. Finally, modifications to the experimental setup are suggested that should lead to improvement in the extraction current and spot size of focused electron beams and also better understanding of the processes taking place in the experiment. Y1 - 2024 SN - 979-8-3503-7976-1 U6 - https://doi.org/10.1109/IVNC63480.2024.10652470 SP - 1 EP - 2 PB - IEEE ER - TY - JOUR A1 - Schmidt, Oliver G. A1 - Denker, Ullrich A1 - Dashiell, Michael W. A1 - Jin-Phillipp, Neng Yun A1 - Eberl, Karl A1 - Schreiner, Rupert A1 - Gräbeldinger, Hedwig A1 - Schweizer, Heinz C. A1 - Christiansen, Silke H. A1 - Ernst, Frank T1 - Laterally aligned Ge/Si islands: a new concept for faster field-effect transistors JF - Materials Science and Engineering B N2 - Self-assembled and coherently strained Ge dots were grown on a Si/SiGe superlattice, which was deposited on a flat Si(001) substrate surface patterned with a regular array of straight trenches. The superlattice translates the surface modulation of the substrate into a strain-field modulation, which causes the Ge dots on its surface to form along straight lines above the buried trenches. This approach provides self-assembled Ge dots with excellent lateral periodicity, which might be useful for fabricating dot-based field-effect-transistors (DotFETs). Here, we propose the concept of a modulation-doped p-channel DotFET (p-MOD-DotFET). The p-MOD-DotFET relies on embedded Ge-rich nanostructures, which provide p-channels through the Ge-rich dots. A high Ge concentration in the dots is desirable in order to exploit the high hole mobility of Ge-rich material. We show that the commonly observed Si–Ge intermixing during Si capping of Ge dots can be suppressed by overgrowing the islands at low temperature. KW - Field-effect transistor KW - Self-assembly islands KW - CMOS KW - MOSFET KW - MOFDET alignment KW - Modulation Y1 - 2002 U6 - https://doi.org/10.1016/S0921-5107(01)00810-8 SN - 1873-4944 SN - 0921-5107 VL - 89 IS - 1-3 SP - 101 EP - 105 PB - Elsevier CY - New York, NY ER - TY - CHAP A1 - Eiler, Julian A1 - Högl, Christina A1 - Lindner, Matthias A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Miniaturized Surface Dielectric Barrier Discharge Plasma Actuators for Application in Chemical Analysis Systems T2 - 2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA N2 - A new concept for a miniaturized planar ion source based on a surface dielectric barrier discharge (SDBD) is presented. A fabrication method based on a stamping process is described, and the plasma actuators are characterized based on their power in dependence of the applied voltage. The voltage for plasma ignition is approx. 1 kV with a maximum plasma power of 40 W/m at 3,4 kV. KW - Actuators KW - Discharges (electric) KW - Ion sources KW - Low Temperature Plasma KW - Plasma KW - Plasma Actuator KW - Plasmas KW - Surface Dielectric Barrier Discharge KW - Surface discharges KW - Vacuum systems KW - Voltage Y1 - 2023 SN - 979-8-3503-0143-4 U6 - https://doi.org/10.1109/IVNC57695.2023.10188884 SP - 40 EP - 42 PB - IEEE ER - TY - CHAP A1 - Bartl, Mathias A1 - Buchner, Philipp A1 - Hausladen, Matthias A1 - Asgharzadehkhorasani, Ali A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Simulations and Investigations of Silicon Nanowire Field Emitters T2 - 37th International Vacuum Nanoelectronics Conference (IVNC), 15-19 July 2024, Brno, Czech Republic N2 - The emission behavior of field emission electron sources consisting of a silicon nanowire cathode, an extraction grid electrode and a planar anode was investigated based on a particle tracing simulation using FEM. The focus was on the influence of the grid geometry as well as the positioning of the grid relative to the emitters on the electron transmission. The highest transmission can be achieved with the emitter tips protruding 10 µm trough the extraction grid openings. The transmission decreases more rapidly with increasing distance between the tip and the grid the thicker the grid is. Y1 - 2024 U6 - https://doi.org/10.1109/IVNC63480.2024.10652355 SP - 1 EP - 2 PB - IEEE ER - TY - JOUR A1 - Hausladen, Matthias A1 - Buchner, Philipp A1 - Bartl, Mathias A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Integrated multichip field emission electron source fabricated by laser-micromachining and MEMS technology JF - Journal of Vacuum Science & Technology B N2 - In this work, high-current field emission electron source chips were fabricated using laser-micromachining and MEMS technology. The resulting chips were combined with commercially available printed circuit boards (PCBs) to obtain a multichip electron source. By controlling the separate electron sources using an external current control circuit, we were able to divide the desired total current evenly across the individual chips deployed in the PCB-carrier. In consequence, we were able to show a decreased degradation due to the reduced current load per chip. First, a single electron source chip was measured without current regulation. A steady-state emission current of 1 mA with a high stability of ±1.3% at an extraction voltage of 250 V was observed. At this current level, a mean degradation slope of −0.7 μA/min with a nearly perfect transmission ratio of 99% ± 0.4% was determined. The measurements of a fully assembled multichip PCB-carrier electron source, using a current control circuit for regulation, showed that an even distribution of the desired total current led to a decreased degradation. This was determined by the increase in the required extraction voltage over time. For this purpose, two current levels were applied to the electron source chips of the PCB-carrier using an external current control circuit. First, 300 μA total current was evenly distributed among the individual electron source chips followed by the emission of 300 μA per electron source chip. This allows the observation of the influence of a distributed and nondistributed total current, carried by the electron source chips. Thereby, we obtained an increase in the mean degradation slope from +0.011 V/min (300 μA distributed) to +0.239 V/min (300 μA per chip), which is approximately 21 times higher. Moreover, our current control circuit improved the current stability to under 0.1% for both current levels, 300 μA distributed and 300 μA per chip. KW - MEMS technology KW - Field emitter arrays KW - Electron sources KW - Laser micromachining Y1 - 2024 U6 - https://doi.org/10.1116/6.0003233 VL - 42 IS - 1 PB - AIP Publishing ER - TY - JOUR A1 - Remškar, Maja A1 - Jelenc, Janez A1 - Czepurnyi, Nikolai A1 - Malok, Matjaž A1 - Pirker, Luka A1 - Schreiner, Rupert A1 - Hüttel, Andreas K. T1 - Modulations of the work function and morphology of a single MoS2 nanotube by charge injection JF - Nanoscale Advances N2 - Both the miniaturization of transistor components and the ongoing investigation of material systems with potential for quantum information processing have significantly increased current interest of researchers in semiconducting inorganic nanotubes. Here we report on an additional outstanding aspect of these nanostructures, namely the intrinsic coupling of electronic and mechanical properties. We observe electronic and morphology changes in a single MoS2 nanotube, exposed to charge injections by means of an atomic-force-microscopy tip. An elliptic deformation of the nanotube and helical twisting of the nanotube are visible, consistent with the reverse piezoelectric effect. Work-function changes are found to be dependent on the polarity of the injected carriers. An unexpected long-term persistence of the shape deformations is observed and explained with accumulation of structural defects and the resultant strain, which could cause a memory-like charge confinement and a long lasting modulation of the work function. Y1 - 2024 U6 - https://doi.org/10.1039/d4na00490f SN - 2516-0230 PB - Royal Society of Chemistry (RSC) ER - TY - JOUR A1 - Lindner, Matthias A1 - Pipa, Andrei V. A1 - Karpen, Norbert A1 - Hink, Rüdiger A1 - Berndt, Dominik A1 - Foest, Rüdiger A1 - Bonaccurso, Elmar A1 - Weichwald, Robert A1 - Friedberger, Alois A1 - Caspari, Ralf A1 - Brandenburg, Ronny A1 - Schreiner, Rupert T1 - Icing Mitigation by MEMS-Fabricated Surface Dielectric Barrier Discharge JF - Applied Sciences N2 - Avoiding ice accumulation on aerodynamic components is of enormous importance to flight safety. Novel approaches utilizing surface dielectric barrier discharges (SDBDs) are expected to be more efficient and effective than conventional solutions for preventing ice accretion on aerodynamic components. In this work, the realization of SDBDs based on thin-film substrates by means of micro-electro-mechanical-systems (MEMS) technology is presented. The anti-icing performance of the MEMS SDBDs is presented and compared to SDBDs manufactured by printed circuit board (PCB) technology. It was observed that the 35 mu m thick electrodes of the PCB SDBDs favor surface icing with an initial accumulation of supercooled water droplets at the electrode impact edges. This effect was not observed for 0.3 mu m thick MEMS-fabricated electrodes indicating a clear advantage for MEMS-technology SDBDs for anti-icing applications. Titanium was identified as the most suitable material for MEMS electrodes. In addition, an optimization of the MEMS-SDBDs with respect to the dielectric materials as well as SDBD design is discussed. KW - aerospace engineering KW - anti-icing KW - DBD PLASMA ACTUATORS KW - EXCITATION KW - FLOW-CONTROL KW - low-temperature plasma KW - MEMS KW - SEPARATION CONTROL KW - SDBD Y1 - 2021 U6 - https://doi.org/10.3390/app112311106 N1 - Corresponding author: Matthias Lindner VL - 11 IS - 23 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Scharfenberg, Georg A1 - Mottok, Jürgen A1 - Artmann, Christina A1 - Hobelsberger, Martin A1 - Paric, Ivan A1 - Großmann, Benjamin A1 - Pohlt, Clemens A1 - Wackerbarth, Alena A1 - Pausch, Uli A1 - Heidrich, Christiane A1 - Fadanelli, Martin A1 - Elsner, Michael A1 - Pöcher, Daniel A1 - Pittroff, Lenz A1 - Beer, Stefan A1 - Brückl, Oliver A1 - Haslbeck, Matthias A1 - Sterner, Michael A1 - Thema, Martin A1 - Muggenthaler, Nicole A1 - Lenck, Thorsten A1 - Götz, Philipp A1 - Eckert, Fabian A1 - Deubzer, Michael A1 - Stingl, Armin A1 - Simsek, Erol A1 - Krämer, Stefan A1 - Großmann, Benjamin A1 - Schlegl, Thomas A1 - Niedersteiner, Sascha A1 - Berlehner, Thomas A1 - Joblin, Mitchell A1 - Mauerer, Wolfgang A1 - Apel, Sven A1 - Siegmund, Janet A1 - Riehle, Dirk A1 - Weber, Joachim A1 - Palm, Christoph A1 - Zobel, Martin A1 - Al-Falouji, Ghassan A1 - Prestel, Dietmar A1 - Scharfenberg, Georg A1 - Mandl, Roland A1 - Deinzer, Arnulf A1 - Halang, W. A1 - Margraf-Stiksrud, Jutta A1 - Sick, Bernhard A1 - Deinzer, Renate A1 - Scherzinger, Stefanie A1 - Klettke, Meike A1 - Störl, Uta A1 - Wiech, Katharina A1 - Kubata, Christoph A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. A1 - Dollinger, Markus A1 - Dembianny, Sven A1 - Kölbl, Andreas A1 - Welker, Franz A1 - Meier, Matthias A1 - Thumann, Philipp A1 - Swidergal, Krzysztof A1 - Wagner, Marcus A1 - Haug, Sonja A1 - Vernim, Matthias A1 - Seidenstücker, Barbara A1 - Weber, Karsten A1 - Arsan, Christian A1 - Schone, Reinhold A1 - Münder, Johannes A1 - Schroll-Decker, Irmgard A1 - Dillinger, Andrea Elisabeth A1 - Fuchshofer, Rudolf A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail A1 - Geith, Markus A. A1 - Koch, Fabian A1 - Ühlin, Christian A1 - Schratzenstaller, Thomas A1 - Saßmannshausen, Sean Patrick A1 - Auchter, Eberhard A1 - Kriz, Willy A1 - Springer, Othmar A1 - Thumann, Maria A1 - Kusterle, Wolfgang A1 - Obermeier, Andreas A1 - Udalzow, Anton A1 - Schmailzl, Anton A1 - Hierl, Stefan A1 - Langer, Christoph A1 - Schreiner, Rupert ED - Baier, Wolfgang T1 - Forschungsbericht 2015 T3 - Forschungsberichte der OTH Regensburg - 2015 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-13867 SN - 978-3-00-048589-3 CY - Regensburg ER - TY - CHAP A1 - Krysztof, Michał A1 - Urbański, Paweł A1 - Grzebyk, Tomasz A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - MEMS X-Ray Source: Electron Emitter Development T2 - 2022 21st International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS): 12-15 Dec. 2022, Salt Lake City, UT, USA N2 - The article presents a fabrication process and characterization of silicon emitters designed for MEMS X-ray source. The emitters, made of p-type and n-type silicon, were prepared by a modified laser micromachining process. Both types of emitters worked without any carbon nanotube coverage, which was the case in the previous realization of electron emitters. The p-type emitter gave smaller electron beam currents (<50 nA) with stable emission in a saturation region. The n-type emitter provides higher emission currents (>1 µA) not limited by saturation region, but with higher fluctuations. The final choice of emitter will be adjusted for different applications. KW - Micromechanical devices KW - MEMS KW - X-ray source KW - electron emitter KW - X-ray radiation Y1 - 2022 U6 - https://doi.org/10.1109/PowerMEMS56853.2022.10007563 SP - 248 EP - 251 PB - IEEE ER - TY - JOUR A1 - Beimler, Josef A1 - Leißl, Caroline A1 - Ebner, Lena A1 - Elsner, Michael A1 - Mühlbauer, Gerhard A1 - Kohlert, Dieter A1 - Schubert, Martin J. W. A1 - Weiß, Andreas P. A1 - Sterner, Michael A1 - Raith, Thomas A1 - Afranseder, Martin A1 - Krapf, Tobias A1 - Mottok, Jürgen A1 - Siemers, Christian A1 - Großmann, Benjamin A1 - Höcherl, Johannes A1 - Schlegl, Thomas A1 - Schneider, Ralph A1 - Milaev, Johannes A1 - Rampelt, Christina A1 - Roduner, Christian A1 - Glowa, Christoph A1 - Bachl, Christoph A1 - Schliekmann, Claus A1 - Gnan, Alfons A1 - Grill, Martin A1 - Ruhland, Karl A1 - Piehler, Thomas A1 - Friers, Daniel A1 - Wels, Harald A1 - Pflug, Kenny A1 - Kucera, Markus A1 - Waas, Thomas A1 - Schlachetzki, Felix A1 - Boy, Sandra A1 - Pemmerl, Josef A1 - Leis, Alexander A1 - Welsch, Andreas F.X. A1 - Graf, Franz A1 - Zenger, Gerhard A1 - Volbert, Klaus A1 - Waas, Thomas A1 - Scherzinger, Stefanie A1 - Klettke, Meike A1 - Störl, Uta A1 - Heyl, C. A1 - Boldenko, A. A1 - Monkman, Gareth J. A1 - Kujat, Richard A1 - Briem, Ulrich A1 - Hierl, Stefan A1 - Talbot, Sebastian A1 - Schmailzl, Anton A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Valentino, Piergiorgio A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Furgiuele, Franco A1 - Gebbeken, Norbert A1 - Eisenried, Michael A1 - Jungbauer, Bastian A1 - Hutterer, Albert A1 - Bauhuber, Michael A1 - Mikrievskij, Andreas A1 - Argauer, Monika A1 - Hummel, Helmut A1 - Lechner, Alfred A1 - Liebetruth, Thomas A1 - Schumm, Michael A1 - Joseph, Saskia A1 - Reschke, Michael A1 - Soska, Alexander A1 - Schroll-Decker, Irmgard A1 - Putzer, Michael A1 - Rasmussen, John A1 - Dendorfer, Sebastian A1 - Weber, Tim A1 - Al-Munajjed, Amir Andreas A1 - Verkerke, Gijsbertus Jacob A1 - Renkawitz, Tobias A1 - Haug, Sonja A1 - Rudolph, Clarissa A1 - Zeitler, Annika A1 - Schaubeck, Simon A1 - Steffens, Oliver A1 - Rechenauer, Christian A1 - Schulz-Brize, Thekla A1 - Fleischmann, Florian A1 - Kusterle, Wolfgang A1 - Beer, Anne A1 - Wagner, Bernd A1 - Neidhart, Thomas ED - Baier, Wolfgang T1 - Forschungsbericht 2013 T3 - Forschungsberichte der OTH Regensburg - 2013 Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-7990 CY - Regensburg ER - TY - JOUR A1 - Mauerer, Wolfgang A1 - Rexhepaj, Tanja A1 - Monkman, Gareth J. A1 - Sindersberger, Dirk A1 - Diermeier, Andreas A1 - Neidhart, Thomas A1 - Wolfrum, Dominik A1 - Sterner, Michael A1 - Heberl, Michael A1 - Nusko, Robert A1 - Maier, Georg A1 - Nagl, Klaus A1 - Reuter, Monika A1 - Hofrichter, Andreas A1 - Lex, Thomas A1 - Lesch, Florian A1 - Kieninger, Bärbel A1 - Szalo, Alexander Eduard A1 - Zehner, Alexander A1 - Palm, Christoph A1 - Joblin, Mitchell A1 - Apel, Sven A1 - Ramsauer, Ralf A1 - Lohmann, Daniel A1 - Westner, Markus A1 - Strasser, Artur A1 - Munndi, Maximilian A1 - Ebner, Lena A1 - Elsner, Michael A1 - Weiß, Nils A1 - Segerer, Matthias A1 - Hackenberg, Rudolf A1 - Steger, Sebastian A1 - Schmailzl, Anton A1 - Dostalek, Michael A1 - Armbruster, Dominik A1 - Koch, Fabian A1 - Hierl, Stefan A1 - Thumann, Philipp A1 - Swidergal, Krzysztof A1 - Wagner, Marcus A1 - Briem, Ulrich A1 - Diermeier, Andreas A1 - Spreitzer, Stefan A1 - Beiderbeck, Sabrina A1 - Hook, Christian A1 - Zobel, Martin A1 - Weber, Tim A1 - Groß, Simon A1 - Penzkofer, Rainer A1 - Dendorfer, Sebastian A1 - Schillitz, Ingo A1 - Bauer, Thomas A1 - Rudolph, Clarissa A1 - Schmidt, Katja A1 - Liebetruth, Thomas A1 - Hamer, Markus A1 - Haug, Sonja A1 - Vernim, Matthias A1 - Weber, Karsten A1 - Saßmannshausen, Sean Patrick A1 - Books, Sebastian A1 - Neuleitner, Nikolaus A1 - Rechenauer, Christian A1 - Steffens, Oliver A1 - Kusterle, Wolfgang A1 - Gömmel, Roland A1 - Wellnitz, Felix A1 - Stierstorfer, Johannes A1 - Stadler, Dominik A1 - Hofmann, Matthias J. A1 - Motschmann, Hubert A1 - Shamonin (Chamonine), Mikhail A1 - Bleicher, Veronika A1 - Fischer, Sebastian A1 - Hackenberg, Rudolf A1 - Horn, Anton A1 - Kawasch, Raphael A1 - Petzenhauser, Michael A1 - Probst, Tobias A1 - Udalzow, Anton A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian ED - Baier, Wolfgang T1 - Forschungsbericht 2016 T3 - Forschungsberichte der OTH Regensburg - 2016 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-13840 CY - Regensburg ER - TY - JOUR A1 - Lautenschläger, Toni A1 - Leis, Alexander A1 - Dendorfer, Sebastian A1 - Palm, Christoph A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Dams, Florian A1 - Bornmann, Benjamin A1 - Navitski, Aliaksandr A1 - Serbun, Pavel A1 - Müller, Günter A1 - Liebetruth, Thomas A1 - Kohlert, Dieter A1 - Pernsteiner, Jochen A1 - Schreier, Franz A1 - Heerklotz, Sabrina A1 - Heerklotz, Allwin A1 - Boos, Alexander A1 - Herwald, Dominik A1 - Monkman, Gareth J. A1 - Treiber, Daniel A1 - Mayer, Matthias A1 - Hörner, Eva A1 - Bentz, Alexander A1 - Shamonin (Chamonine), Mikhail A1 - Johansen, Søren Peter A1 - Reichel, Marco A1 - Stoll, Andrea A1 - Briem, Ulrich A1 - Dullien, Silvia A1 - Renkawitz, Tobias A1 - Weber, Tim A1 - Dendorfer, Sebastian A1 - Grifka, Joachim A1 - Penzkofer, Rainer A1 - Barnsteiner, K. A1 - Jovanovik, M. A1 - Wernecke, P. A1 - Vögele, A. A1 - Bachmann, T. A1 - Plötz, Martin A1 - Schliekmann, Claus A1 - Wels, Harald A1 - Helmberger, Paul A1 - Kaspar, Marcel A1 - Hönicka, M. A1 - Schrammel, Siegfried A1 - Enser, Markus A1 - Schmidmeier, Monika A1 - Schroll-Decker, Irmgard A1 - Haug, Sonja A1 - Gelfert, Verena A1 - Vernim, Matthias ED - Baier, Wolfgang T1 - Forschungsbericht 2012 T3 - Forschungsberichte der OTH Regensburg - 2012 Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-7834 CY - Regensburg ER - TY - JOUR A1 - Appelhans, Marie-Luise A1 - Kampmann, Matthias A1 - Mottok, Jürgen A1 - Riederer, Michael A1 - Nagl, Klaus A1 - Steffens, Oliver A1 - Dünnweber, Jan A1 - Wildgruber, Markus A1 - Roth, Julius A1 - Stadler, Timo A1 - Palm, Christoph A1 - Weiß, Martin Georg A1 - Rochholz, Sandra A1 - Bierl, Rudolf A1 - Gschossmann, Andreas A1 - Haug, Sonja A1 - Schmidbauer, Simon A1 - Koch, Anna A1 - Westner, Markus A1 - Bary, Benedikt von A1 - Ellermeier, Andreas A1 - Vögele, Daniel A1 - Maiwald, Frederik A1 - Hierl, Stefan A1 - Schlamp, Matthias A1 - Ehrlich, Ingo A1 - Siegl, Marco A1 - Hüntelmann, Sven A1 - Wildfeuer, Matthias A1 - Brückl, Oliver A1 - Sterner, Michael A1 - Hofrichter, Andreas A1 - Eckert, Fabian A1 - Bauer, Franz A1 - Dawoud, Belal A1 - Rabl, Hans-Peter A1 - Gamisch, Bernd A1 - Schmidt, Ottfried A1 - Heberl, Michael A1 - Thema, Martin A1 - Mayer, Ulrike A1 - Eller, Johannes A1 - Sippenauer, Thomas A1 - Adelt, Christian A1 - Haslbeck, Matthias A1 - Vogl, Bettina A1 - Mauerer, Wolfgang A1 - Ramsauer, Ralf A1 - Lohmann, Daniel A1 - Sax, Irmengard A1 - Gabor, Thomas A1 - Feld, Sebastian A1 - Linnhoff-Popien, Claudia A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Sellmair, Josef ED - Baier, Wolfgang T1 - Forschung 2019 BT - Thema: Künstliche Intelligenz N2 - Bericht mit Forschungsprojekten aus verschiedenen Bereichen der OTH Regensburg mit dem Schwerpunktthema "Künstliche Intelligenz" und einem Gespräch zur "Medizin der Zukunft" T3 - Forschungsberichte der OTH Regensburg - 2019 KW - Forschung KW - Forschungsbericht KW - Künstliche Intelligenz Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-7890 SN - 978-3-9818209-7-3 CY - Regensburg ER - TY - CHAP A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Theoretical investigations into the field enhancement factor of silicon structures T2 - 25th International Vacuum Nanoelectronics Conference (IVNC) - Jeju, Korea (South), 09.- 13.07.2012 N2 - In order to optimize our field-emitting silicon structures, the influence of geometric parameters like aspect ratio, aperture angle and curvature on the field enhancement factor was investigated by finite element simulations. A universal geometric model consisting of a rounded triangle and elliptic curvatures was taken for modeling a variety of different silicon tip as well as ridge structures. Whereas, a high dependency of the field enhancement on the aperture angle was found, the simulations show that the elliptic curvature affects the field enhancement only marginal. KW - elemental semiconductors KW - field emitter arrays KW - field enhancement factor KW - finite element analysis KW - silicon KW - silicon field emitter Y1 - 2012 SN - 978-1-4673-1984-3 SN - 978-1-4673-1983-6 SN - 978-1-4673-1982-9 U6 - https://doi.org/10.1109/IVNC.2012.6316886 SN - 2380-6311 SN - 2164-2370 PB - IEEE CY - Piscataway, N.J. ER - TY - JOUR A1 - Prommesberger, Christian A1 - Bachmann, Michael A1 - Düsberg, Felix A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Schreiner, Rupert T1 - Regulation of the Transmitted Electron Flux in a Field-Emission Electron Source Demonstrated on Si Nanowhisker Cathodes JF - IEEE Transactions on Electron Devices N2 - We report on a method to stabilize the transmitted electron flux in a field-emission electron source using an external regulation circuit. The electron source was realized with an array of silicon (Si) nanowhiskers on the top of elongated pillar structures, a mica spacer, and an extraction grid made of Si. As for most applications, the emitted electron current from the cathode is not as crucial as the transmitted electron flux through the extraction grid toward the anode. We investigated a method which allows the regulation directly by the emitted electron flux and not merely on the cathode current. By using this method, we were able to stabilize the emitted electron flux of our electron source down to values below 1%. Simultaneously, it was shown that there is the possibility to stabilize the influencing value in the real application as well. The effectiveness of this method was demonstrated successfully with an X-ray source setup. The measured X-ray photon count rate was stabilized to a standard deviation of 0.30% at a pressure of 1 × 10 -7 mbar. Even in harsh environment of 2 × 10 -5 mbar, a stabilization of the X-ray photon count rate down to a value of 0.63% was achieved. KW - Cathodes KW - Nanostructured devices KW - Current measurement KW - Photonics KW - Electron sources KW - Emissions KW - Voltage measurement Y1 - 2017 U6 - https://doi.org/10.1109/TED.2017.2763239 SN - 5128-5133 VL - 64 IS - 12 PB - IEEE ER - TY - JOUR A1 - Langer, Christoph A1 - Bomke, Vitali A1 - Hausladen, Matthias A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Silicon Chip Field Emission Electron Source Fabricated by Laser Micromachining JF - Journal of Vacuum Science & Technology B N2 - The components for a silicon chip electron source were fabricated by laser micromachining using pulsed laser ablation and wet chemical cleaning and etching dips. The field emission electron source consists of a silicon field emission cathode with 4 × 4 conical shaped emitters with a height of 250 μm and a tip radius of about 50 nm, a 50 μm thick laser-structured mica spacer, and a silicon grid electrode with a grid periodicity of 200 μm and a bar width of 50 μm. These three components are combined to a single chip with the size of 14 × 10 mm2 and the thickness of 1 mm to form the electron source. Several of these devices were characterized in ultrahigh vacuum. Onset voltages of about 165 V and cathode currents of about 15 μA for voltages lower than 350 V were observed. Operating the electron source with an anode voltage of 500 V and an extraction grid voltage of 300 V yielded a cathode current of 4.5 μA ± 8.9%, an anode current of 4.0 μA ± 9.6%, and a corresponding grid transmittance of 89%. Regulating the anode current by the extraction grid voltage, an extremely stable anode current of 5.0 μA ± 0.017% was observed. A long-term measurement over 120 h was performed, and no significant degradation or failure was observed. KW - Ultra-high vacuum KW - Field emitter arrays KW - Etching KW - Electrical properties and parameters KW - Electron sources KW - Laser ablation KW - Laser micromachining KW - Silicon chip KW - Triodes Y1 - 2020 U6 - https://doi.org/10.1116/1.5134872 VL - 38 IS - 1 PB - AIP Publishing ER - TY - JOUR A1 - Breuer, Janis A1 - Bachmann, Michael A1 - Düsberg, Felix A1 - Pahlke, Andreas A1 - Edler, Simon A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert A1 - Serbun, Pavel A1 - Lützenkirchen-Hecht, Dirk T1 - Extraction of the current distribution out of saturated integral measurement data of p-type silicon field emitter arrays JF - Journal of Vacuum Science and Technology B N2 - At the moment, only complicated techniques are known for the determination of array properties of field emitter arrays such as the number of active tips, the current distribution, or the individual tip radii. In this work, a method for extracting these parameters from integral measurement data is presented. A model describing the characteristics of a single emitter, including the saturation as a function of the applied voltage and the emitter radius, is developed. It is shown that experimental data of field emitter arrays can be represented as the sum of these functions and the characteristic parameters can be fitted to field emission data of an array. Using this method, the values of the radii as well as the parameters of distribution models can be determined directly. Analysis of experimental data from p-type Si emitter arrays shows that only 1–2% of the tips contribute significantly. Y1 - 2018 U6 - https://doi.org/10.1116/1.5035189 VL - 36 IS - 5 PB - AIP Publishing ER - TY - JOUR A1 - Edler, Simon A1 - Bachmann, Michael A1 - Breuer, Janis A1 - Dams, Florian A1 - Düsberg, Felix A1 - Hofmann, Martin A1 - Jakšič, Jasna A1 - Pahlke, Andreas A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Influence of adsorbates on the performance of a field emitter array in a high voltage triode setup JF - Journal of Applied Physics N2 - In the present work, black-silicon field emitter arrays (FEAs) are investigated regarding the influence of residual gas pressure on the characteristics and lifetime in the high voltage triode setup. Current-voltage-characteristics at different pressure levels are recorded and show a decreasing emission current with rising pressure. This decrease can be explained by an increase of the work function and charging of the emitter surface caused by adsorbates. The emission current can be restored to its initial value by heating of the FEA up to 110 °C during active emission. With this regeneration procedure, an extended lifetime from about 20 h to 440 h at a residual gas pressure of 10−5 mbar is achieved. Y1 - 2017 U6 - https://doi.org/10.1063/1.4987134 VL - 122 ER - TY - JOUR A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert A1 - Serbun, Pavel A1 - Müller, Günter A1 - Düsberg, Felix A1 - Hofmann, Martin A1 - Bachmann, Michael A1 - Pahlke, Andreas T1 - Field emission properties of p-type black silicon on pillar structures JF - Journal of Vacuum Science & Technology B N2 - Arrays of black silicon field emission pillar structures were fabricated on p-type silicon substrates. Two types of samples with the same number of pillars (arrays of 10 × 10) but different pillar heights (8 and 20 μm) were prepared as well as a black silicon reference sample without pillars. The field emission properties of these cathodes were investigated both by means of integral current-voltage measurements and by field emission scanning microscopy. Samples with a pillar height of 20 μm revealed onset fields as low as 6.4 V/μm, field enhancement factors up to 800, and emission currents up to 8 μA at an applied field of 20 V/μm. Due to the p-type material, a saturation of the emission current for fields above 11 V/μm was observed. This saturation leads to a stable operation with a current fluctuation of less than ±8%. It was found that samples with a pillar height of 20 μm showed improved emission characteristics compared to samples with a pillar height of 8 μm or without pillars. The voltage maps revealed an increased emission homogeneity after a “burn-in” sequence of the sample. The current map showed that a few of the pillars dominate the emission. Integral current stability measurements were performed under different vacuum pressures, in order to investigate altered emission behavior and a potential degradation of the emitters. At pressures above 10−6 mbar, the sample starts to degrade irreversibly. Nevertheless, even after a harsh treatment over 30 min at 5 × 10−5 mbar and at an applied field of 23 V/μm, the cathode was still operating, and did not fail during further operation over 20 h at 5 × 10−8 mbar and at an applied field of 28 V/μm. Y1 - 2016 U6 - https://doi.org/10.1116/1.4943919 VL - 34 IS - 2 ER - TY - JOUR A1 - Bachmann, Michael A1 - Dams, Florian A1 - Düsberg, Felix A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Schreiner, Rupert A1 - Serbun, Pavel A1 - Lützenkirchen-Hecht, Dirk A1 - Müller, Günter T1 - Extraction of the characteristics of current-limiting elements from field emission measurement data JF - Journal of Vacuum Science & Technology B N2 - In this contribution, the authors will present an algorithm to extract the characteristics of nonideal field emission circuit elements from saturation-limited field emission measurement data. The method for calculating the voltage drop on current-limiting circuit elements is based on circuit theory as well as Newton's method. Since the only assumption the authors make on the current-limiting circuit is a connection in series, this method is applicable to most field emission data showing saturation. To be able to determine the significance of any parameter output, the uncertainties of data and extracted parameters as well as the parameter correlations are fully taken into account throughout the algorithm. N-type silicon samples with varying external serial resistors are analyzed. All results show a good agreement to the nominal resistor values. Additionally, several p-type samples are analyzed, showing a diodelike behavior. The extracted current-limiting characteristics of the p-type samples are in good agreement with a pn-junction model. The stability of the emission current of the p-type samples is measured by constant voltage measurements and compared to the extracted current-limiting characteristics. The application of the algorithm to measurement data shows that the given algorithm is a valuable tool to analyze field emission measurement data influenced by nonemissive processes. Y1 - 2017 U6 - https://doi.org/10.1116/1.4971768 VL - 35 IS - 2 ER - TY - CHAP A1 - Langer, Christoph A1 - Hausladen, Matthias A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Bachmann, Michael A1 - Düsberg, Felix A1 - Pahlke, Andreas A1 - Shamonin (Chamonine), Mikhail A1 - Schreiner, Rupert T1 - Field emission current investigation of p-type and metallized silicon emitters in the frequency domain T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - We investigated two different field emitter arrays consisting of 10×10 p-type and 10×10 undoped Au-coated high aspect ratio silicon tips. The I-V characterization of the p-type sample showed a pronounced saturation for voltages higher than 500 V and a maximum emission current of 39 nA. The metallized sample revealed a FN-like emission up to several μA. The metallized and the p-type sample operating below the saturation region showed high current fluctuations of ±16%. Whereas, the metallized sample with current regulation and the p-type sample in the saturation yielded a current stability of ±0.4% and ±0.3%, respectively. Investigations in the frequency domain revealed the for field emission typical 1/f-noise. By operating in the saturation region (p-type sample) or using an emission current regulation (metallized sample) the noise level was reduced by at least 20 dB. Finally, the p-type sample was illuminated by a light emitting diode to increase and modulate the emission current in the saturation region. The emission current was increased by a factor of 3.7 to 145 nA. With this configuration we emulated an unstable emission behavior and evaluated the performance of our emission current regulation circuit. KW - field emission KW - field emitter array KW - silicon tip KW - current fluctuation KW - current stability KW - field emission noise Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520127 PB - IEEE ER - TY - JOUR A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Investigations on the long-term performance of gated p-type silicon tip arrays with reproducible and stable field emission behavior JF - Journal of Vacuum Science & Technology B N2 - The authors report on the fabrication and characterization of p-type Si tip arrays with an integrated gate electrode for applications as field emission electron sources. After the reactive ion etching of the emitters, the combined thermal dry and wet oxidation was used for both the sharpening of the emitters and for the realization of an enhanced insulation layer. Au was evaporated in a self-aligned process as gate electrode. Arrays of 16 Si tips were fabricated with tip heights of about 3 μm and tip radii of about 20 nm with integrated gate electrode concentrically positioned ≈2 μm below the tip apex. Integral measurements with an additional anode showed improved field emission properties with a reproducible and stable emission behavior. A fast activation of the tips, low onset voltages of about 30 V, and moderate field emission currents up to 0.55 μA were noticed. The field emission parameters were calculated using the Fowler–Nordheim characteristics. A pronounced saturation regime was observed, and current fluctuations of less than ±1% were investigated for 30 min. Long-term measurements were carried out for a period of more than 8 h. In the first 6 h of operation, the authors observed a drift of the emission current from 0.35 to 0.55 μA caused by an increased emission surface. Y1 - 2017 U6 - https://doi.org/10.1116/1.4972519 VL - 35 IS - 1 ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Individually Addressable Fully Integrated Field Emission Electron Source Fabricated by Laser Micromachining of Silicon T2 - 33rd International Vacuum Nanoelectronics Conference (IVNC): 6-10 July 2020, Lyon N2 - A cathode with individually addressable Si tips allows the observation of the activation procedure and emission behaviour of each field emission emitter at any time of the measurement. The cathode consists of an array of 2x2 conically shaped emitter structures, which were fabricated by laser micromachining and wet etching of a Si substrate bonded on a glass carrier. Using the same process, a Si extractions grid was fabricated and mounted onto the emitter. Integral field emission measurements were performed in a diode configuration in a vacuum chamber at pressures of about 10- 9 mbar. The emitters show an onset voltage between 200 V and 300 V. The emission current for each emitter on the cathode was regulated to a given value (1.0 μA, 2.5μA, 5.0μA) by an external regulating circuit and was recorded individually during the measurement. With such approach, the relation between the emission behaviour and the geometry of emitters can be studied in detail. In addition, the current stabilization of each emitters of an array can be investigated, which led to a current stability of better than 0.5%. Y1 - 2020 SN - 978-1-7281-9454-7 U6 - https://doi.org/10.1109/IVNC49440.2020.9203470 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Mecani, Mirgen A1 - Huang, Yifeng A1 - She, Juncong A1 - Schreiner, Rupert ED - Tiginyanu (Ed.), Ion M. T1 - Field emission properties of ring-shaped Si ridges with DLC coating T2 - Proc. SPIE 10248, Nanotechnology VIII, 102480H (30 May 2017) N2 - We report on the fabrication and the emission characterization of single ring-shaped Si ridges with a coating of diamond-like carbon (DLC). The reactive ion etching and the subsequent inductively coupled plasma step were adjusted to realize ring-shaped Si ridges with a height of 7.5 μm respectively 15 μm and an apex radius of 20 – 25 nm. The samples were coated with a DLC layer (thickness ≈ 2 – 5 nm) by a filtered cathodic vacuum arc deposition system in order to lower the work function of the emitter and to improve the field emission characteristics. The field emission characterizations were done in diode configuration with cathode and anode separated by a 50 μm thick mica spacer. A higher emission current was carried out for the ring-shaped Si ridge in comparison to the point-shaped Si tips due to the increased emission area. The highest emission current of 0.22 μA at 1000 V was measured on a DLC-coated sample with the highest aspect ratio. No degradation of the emission current was observed in the plateau regime during a measurement period of 6 h. Finally, no decreasing performance of the field emission properties was found due to changes in the geometry or destructions. KW - Etching KW - Scanning electron microscopy KW - Silicon carbide KW - Carbon KW - Mica KW - Oxides Y1 - 2017 U6 - https://doi.org/10.1117/12.2265627 VL - 102480H PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Field emission from three-dimensional epitaxial grown GaN-microrods T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - A novel three-dimensional epitaxial technique allows on patterned substrates the realization of gallium nitride pillars, also known as nano- and microrods. The typical dimensions of the microrods are in the range of one micron for the radius of the hexagonal footprint and about 10 μm in height. The microrods consist of a semiconductor heterostructure with an n GaN core, a n-GaN shell, a p GaN shell and an intermediate quantum well layer. The field emission properties were investigated in diode configuration by integral field emission measurements in a vacuum chamber at pressures around 10 -9 mbar. The spacer was mica with a thickness of 50 μm. A metallized fine-meshed nitride grid (or a metallized Si-grid) was used as anode. A current of about 1 μA at a voltage of 1250 V (1750 V) was measured. An onset field of about 12.5 MV/m (20 MV/m) and field enhancement factors in the range of 200 to 500 (150 to 300) were found. The investigation with the fine-meshed grid showed an expected pronounced saturation region. KW - field emission KW - GaN KW - LED Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551477 SN - 2380-6311 SP - 87 EP - 88 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Field emission from black silicon structures with integrated gate electrode T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - Black silicon structures with integrated gate electrode were realized by using an improved fabrication process. An enhanced insulation layer was achieved by a combination of dry and wet oxidation, and a gold layer was evaporated as gate electrode. The black silicon structures were prepared with a RIE/ICP etching process at room temperature. Arrays of 16 and 100 apertures with buried p-doped black silicon whiskers have been fabricated. These structures have an emitter height of approximately 1.5 μm with tip radii between 5 nm and 30 nm. The whiskers are surrounded by the gate electrode in a distance of 1.5 μm. Integral field emission measurements yielded an onset voltage of 92 V for 16 apertures and 60 V for 100 apertures for an emission current of 1 nA. Maximum emission currents up to 0.2 μA were observed for the array with 100 apertures at a cathode voltage of 200 V. Stability measurements showed a current fluctuation of ± 21% at a mean value of the emission current of 12 nA over a period of 30 minutes for 16 apertures with b-Si whiskers. KW - field emission KW - black silicon KW - integrated gate electrode Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551532 SN - 2380-6311 SP - 219 EP - 220 PB - IEEE ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Microrods and microlines by three-dimensional epitaxially grown GaN for field emission cathodes T2 - International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg N2 - The three-dimensional epitaxial technique allows the realization of gallium nitride lines in addition to the rods. To optimize the properties of GaN-based field emission cathodes further investigations and an improvement of the epitaxial process were performed. The microrods and microlines consist of a one-order higher n-doped gallium nitride in comparison to the gallium nitride layer on the sapphire substrate. The typical height of the microrods and -lines is about 5 μm. The field emission properties of these structures were investigated in diode configuration by integral field emission measurements at pressures below 10 -9 mbar. For the microrods (microlines) a voltage of 1100 V (2000 V) was measured for a field emission current of about 0.5 μA with an onset field of about 12 MV/m (24 MV/m). Furthermore, the field enhancement factors for microrods and -lines are in the range of 300 and 200, respectively. KW - field emission KW - GaN KW - LED KW - Gallium nitride KW - Epitaxial growth Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051576 SP - 130 EP - 131 PB - IEEE ER - TY - CHAP A1 - Bachmann, Michael A1 - Dams, Florian A1 - Düsberg, Felix A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Extraction of the characteristics of limiting elements from field emission measurement data T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - In this contribution we will present an algorithm to extract the characteristics of non-Fowler-Nordheim (FN) circuit elements from saturation limited field emission (FE) measurement data. The method for calculating the voltage drop on limiting circuit elements is based on circuit theory as well as Newton's method. Since no assumption on the limiting circuit is made, this method is applicable to any FE data showing saturation. To be able to determine the significance of any parameter output, the uncertainties of data and extracted parameters are fully taken into account throughout the algorithm. External serial resistors and a limiting p-doped substrate are analyzed, where the latter shows a diode-like behavior. Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551474 SN - 2380-6311 SP - 81 EP - 82 PB - IEEE ER - TY - CHAP A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert A1 - Huang, Yifeng A1 - She, Juncong T1 - Gated p-Si field emission cathode applied in an ionization vacuum gauge T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - A commercial Bayard-Alpert ionization vacuum gauge was equipped with a field emission electron source based on a cathode consisting of an array of 16 gated, p-doped, and DLC-coated Si-tips and characterized. An anode current of about 1.3 μA led to an ion current of 7 fA at 3×10 -7 mbar and 0.8 pA at 4×10 -5 mbar. Whereas at pressures higher than 4×10 -5 mbar the emission current of the electron source decreased, the ratio of ion and anode current remained linear. A nearly constant sensitivity of ~ 17 mbar -1 of the ionization vacuum gauge within the investigated pressure range was depicted. KW - field emission KW - field emitter array KW - Si KW - DLC KW - electron source KW - ionization vacuum gauge Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551500 SN - 2380-6311 SP - 145 EP - 146 PB - IEEE ER - TY - CHAP A1 - Bachmann, Michael A1 - Dams, Florian A1 - Düsberg, Felix A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Control of the electron source current T2 - International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg N2 - A control circuit to stabilize the flux of electrons transmitted through an extractor electrode is presented. By controlling the emission current a fluctuation with a standard deviation of 0.015% is observed. However, the achievable stability of the transmitted electron current is limited due to a variation of the extraction grid current ratio showing a standard deviation of 4.33%. By regulating the difference of the emission current and the extraction grid current an improved stability of the transmitted electron current down to a standard deviation of 0.280% is observed. Even with operation at 2 × 10 -5 mbar a standard deviation of 0.558% is achieved. KW - Standards KW - Circuit stability KW - Power system stability KW - Current measurement KW - Voltage measurement KW - Electron sources KW - Stability analysis Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051550 SP - 66 EP - 67 PB - IEEE ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert A1 - Linghu, Shuangyi A1 - Gu, Fuxing T1 - Field Emission Behaviour of Single-Crystal Pd Nanowires T2 - 33rd International Vacuum Nanoelectronics Conference (IVNC): 6-10 July 2020, Lyon, France N2 - Single-crystal Pd nanowires with typically 100 nm diameters and lengths from several micrometers to tens of micrometers were grown on Al 2 O 3 substrates in a furnace with Ar atmosphere. Integral field emission measurements of such samples after Pd coating (~10 nm) were performed in a diode configuration with a 50 μm mica spacer in a vacuum chamber at pressures of about 10 -9 mbar. The IV measurement of the sample shows an integral emission current up to 2 μA at a voltage of 500 V (10 MV/m) and an onset voltage for a current of 1 nA of about 275 V. The corresponding Fowler-Nordheim plot show a linear behavior, like expected for a metal needle. Y1 - 2020 SN - 978-1-7281-9454-7 U6 - https://doi.org/10.1109/IVNC49440.2020.9203510 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Benzocyclobutene as a novel integrated spacer material in a field emission electron source T2 - International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg N2 - For the realization of a miniaturized field emission electron source we tested benzocyclobutene (BCB) as a new spacer material between cathode and anode. We fabricated black silicon emitters and characterized the emission behavior with an integrated 5 μm thin and large-area spacer of BCB. The integrated BCB layer allows the realization of a compact electron source with only two components consisting of a cathode with BCB and a grid. The comparison with other spacer materials like polyimide (25 μm thickness) or mica (50 μm thickness) revealed for the cathode with BCB a significantly reduced operational voltage of 240 V for a field emission current of 1 μA. KW - field emission KW - benzocyclobutene KW - integrated spacer KW - electron source KW - black silicon Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051605 SP - 192 EP - 193 PB - IEEE ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Light emitting diodes based on three-dimensional epitaxial grown crystalline GaN rods T2 - 7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, München Y1 - 2017 SN - 978-3-8007-4491-6 SP - 131 EP - 134 PB - VDE-Verlag CY - München ER - TY - CHAP A1 - Lindner, Matthias A1 - Berndt, Dominik A1 - Tschurtschenthal, Karl A1 - Ehrlich, Ingo A1 - Jungbauer, Bastian A1 - Schreiner, Rupert A1 - Pipa, Andrei V. A1 - Hink, Rüdiger A1 - Foest, Rüdiger A1 - Brandenburg, Ronny A1 - Neuwirth, Daniel A1 - Karpen, Norbert A1 - Bonaccurso, Elmar A1 - Weichwald, Robert A1 - Max, Alexander A1 - Caspari, Ralf T1 - Aircraft Icing Mitigation by DBD-based Micro Plasma Actuators T2 - AIAA AVIATION 2020 FORUM: June 15-19, 2020 N2 - We present the application of plasma actuators as a technology for ice prevention at airfoils. The miniaturized dielectric barrier discharge (DBD) plasma actuators (PA) were fabricated by means of microelectromechanical systems (MEMS). We elucidate how to make the actuator samples scalable and applicable to any desired shape by the use of flexible inorganic zirconia substrates. For this purpose, we applied our developed embedding method to integrate the micro actuators in modern carbon/glass fiber reinforced polymer (CFRP/GFRP) materials. Next, the embedded actuator samples were mounted on a mechanical air profile-like fixture and placed in the icing wind tunnel iCORE. The samples were tested in rime ice conditions at temperatures of -15 to -20° C and air speeds up to 30 m/s. Unlike other groups we used a thin film zirconia substrate as dielectric for the plasma actuator. Due to the low substrate thickness of just 150 µm, an operating voltage of 2 kVRMS is already sufficient enough for a stable plasma formation. The experiments show that the operated actuator was able to prevent the ice formation and first indications of a De-icing function were also found. Hence, we show that it is feasible to realize an anti-icing system with zirconia-based plasma actuators operated at lower voltages compared to conventional ones. Y1 - 2020 U6 - https://doi.org/10.2514/6.2020-3243 ER - TY - JOUR A1 - Ławrowski, Robert Damian A1 - Hausladen, Matthias A1 - Buchner, Philipp A1 - Schreiner, Rupert T1 - Silicon Field Emission Electron Source With Individually Controllable Single Emitters JF - IEEE Transactions on Electron Devices N2 - An electron source with an array of individually controllable single tips allows the observation of each emitter current simultaneously as well as the measurement of the integral current. Furthermore, the initial activation process of the individual tips and current distribution of the source can be examined. The Si cathode consists of an array of 2 x 2 conically shaped emitter structures on a borosilicate glass substrate. The emitters were fabricated by laser micromachining and wet etching. Integral field emission (FE) measurements were performed in a diode configuration in a vacuum chamber at pressures of about 10(-9) mbar with a self-aligned Si extraction grid, due to adjustment pins. The total emission current was regulated to a predefined value (4.0, 10, 20, 40, and 50 mu A) by an external regulating circuit and recorded individually during the measurement. The onset voltage for a current of 1 nA varied between 320 and 430 V. The voltage conversion factor is in the range of 7.6 x 10(4) cm(-1) to 1.3 x 10(5) cm(-1). Constant currentmeasurementsover a longer periodof time (1800 values with a sample rate of 0.5 Hz) were performed and show a total current fluctuation less than 0.6% due to the regulation circuit. Despite the stable total current in regulated operation, it was observed that the individual emitters fluctuate up to 75% for low (similar to 10(-8) A) and 5% for high (similar to 10(-5) A) currents. KW - Current distribution KW - current limiters KW - electron emission KW - electron sources KW - silicon-on-insulator Y1 - 2021 U6 - https://doi.org/10.1109/TED.2021.3093374 VL - 68 IS - 8 SP - 4116 EP - 4122 PB - IEEE ER - TY - JOUR A1 - Bachmann, Michael A1 - Düsberg, Felix A1 - Pahlke, Andreas A1 - Edler, Simon A1 - Schels, Andreas A1 - Herdl, Florian A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - High current silicon nanowire field emitter arrays JF - Journal of Vacuum Science & Technology B N2 - Arrays of n-doped silicon nanowire field emitters with a high aspect ratio are realized by a novel dry etching technique. Compared to the high current silicon emitters in the literature, the manufacturing process is much simpler and requires only a single photolithography step and two dry etching steps. The cathodes realized with this method exhibit a total current of 20 mA from an active area of 4×4 mm2, which is significantly higher than that for most known structures made from silicon and also represents good performance in comparison with other emitter types, e.g., carbon nanotubes. In addition to characterization in ultrahigh vacuum, measurements at 10−5 mbar are performed and compared with our recent silicon emitters. Compared to these cathodes, the structures with the nanowires exhibit at least two orders of magnitude higher current-carrying capability. Y1 - 2022 U6 - https://doi.org/10.1116/6.0001639 VL - 40 IS - 1 PB - AIP Publishing ER - TY - JOUR A1 - Remskar, Maja A1 - Hüttel, Andreas K. A1 - Shubina, Tatiana V. A1 - Seabaugh, Alan A1 - Fathipour, Sara A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Confinement Related Phenomena in MoS2 Tubular Structures Grown from Vapour Phase JF - Israel Journal of Chemistry N2 - We review recently discovered phenomena observed in the MoS2 tubular structures, which were synthesized by a lasting chemical transport reaction nearly at chemical equilibrium. Such MoS2 nanotubes are distinguished by low density of structural defects, thin walls and a high aspect ratio, which intrinsically provide a confined, edge-free geometry. Quantum confinement with single electron conductance was recorded and a bright exciton photoluminescence with appearance of whispering gallery modes was observed. In addition, the field-effect transistors and field emitters based on single MoS2 nanotubes were demonstrated. These discoveries revitalize research of MoS2 curved structures grown from vapour phase, which were reported several decades ago. Y1 - 2021 U6 - https://doi.org/10.1002/ijch.202100100 SN - 1869-5868 VL - 62 IS - 3-4 SP - 1 EP - 11 PB - Wiley ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Field Emission Arrays from Graphite Fabricated by Laser Micromachining T2 - 34th International Vacuum Nanoelectronics Conference (IVNC): 7/5/2021 - 7/9/2021, Lyon, France N2 - Arrays of 4x4 conical shaped emitters were directly structured by laser micromaching. Assembled as an electron source with a spacer and Si-grid, they were investigated by means of IV-measurement in ultra-high vacuum. The IV-measurements of the sample show integral emission currents up to 10 µA at a voltage of 1000 V (11 MV/m). Initially, an ideal FN-behaviour is noticeable. The deviation for higher voltage values in the FN-plot is caused by the change of the work function, which was proven by numerical calculations. KW - field emission array KW - graphite KW - laser micromachining Y1 - 2021 SN - 978-1-6654-2589-6 U6 - https://doi.org/10.1109/IVNC52431.2021.9600736 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Lindner, Matthias A1 - Berndt, Dominik A1 - Jungbauer, Bastian A1 - Ehrlich, Ingo A1 - Schreiner, Rupert A1 - Pipa, Andrei V. A1 - Hink, Rüdiger A1 - Foest, Rüdiger A1 - Brandenburg, Ronny A1 - Max, Alexander A1 - Caspari, Ralf T1 - Fabrication, surface integration and testing of miniaturized dielectric barrier discharge plasma actuators for active flow control applications T2 - AIAA Aviation 2019 Forum, 17-21 June 2019, Dallas, Texas Y1 - 2019 U6 - https://doi.org/10.2514/6.2019-2998 ER - TY - CHAP A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Dams, Florian A1 - Serbun, Pavel A1 - Bachmann, Michael A1 - Müller, Günter A1 - Schreiner, Rupert T1 - High aspect ratio silicon tip cathodes for application in field emission electron sources T2 - 2014 27th International Vacuum Nanoelectronics Conference (IVNC), 6-10 July 2014, Engelberg, Switzerland N2 - Precisely aligned arrays of sharp tip structures on top of elongated pillars were realized by using an improved fabrication process including an additional inductively-coupled-plasma reactive-ion etching step. Arrays of n-type and p-type silicon with 271 tips have been fabricated and investigated. Those structures have a total height of 5–6 µm and apex radii less than 20nm. Integral field emission measurements of the arrays yielded low onset-fields in the range of 8–12V=µm and field enhancement factors between 300 and 700. The I-E curves of n-type structures showed the usual Fowler-Nordheim behaviour, whereas p-type structures revealed a significant saturation region due to the limited number of electrons in the conduction band and a further carrier depletion effect caused by the pillar. The maximum integral current in the saturation region was 150 nA at fields above 30V=µm. An excellent stability of the emission current of less than ± 2% fluctuation was observed in the saturation region. For n-type Si a maximum integral current of 10 µA at 24V=µm and an average current stability with a fluctuation of ± 50% were measured. KW - Current measurement KW - Etching KW - FABRICATION KW - field emission KW - field emitter array KW - GEOMETRY KW - Iron KW - Sensor arrays KW - silicon KW - silicon tip Y1 - 2014 U6 - https://doi.org/10.1109/IVNC.2014.6894824 SP - 222 EP - 223 PB - IEEE ER - TY - JOUR A1 - Bachmann, Michael A1 - Düsberg, Felix A1 - Langer, Christoph A1 - Herdl, Florian A1 - Bergbreiter, Lukas A1 - Dams, Florian A1 - Miyakawa, Natuski A1 - Eggert, Tobias A1 - Pahlke, Andreas A1 - Edler, Simon A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Vacuum-sealed field emission electron gun JF - Journal of Vacuum Science & Technology B N2 - A compact vacuum-sealed field emission electron gun with an operation voltage below 5 kV is presented. With a 150 nm thick pyrolytic carbon membrane, a transmission of 40% at 5 kV is obtained. For more than 2500 h of continuous operation at an emission current of 100 nA, no significant increase (<50V ) and almost no degradation were found. From this measurement, a lifetime of more than 10 000 h at continuous operation with approximately a linear increase of the extraction voltage from about 545 V to about 730 V is predicted. This electron source enables application of field emitter arrays in poor vacuum or even ambient pressure. ACKNOWLEDGMENT This work was supported by the German Federal Ministry for Economic Affairs and Energy under Project No. ZF4081502GM8. C.P., R.L., M.H., and R.S. were supported by Grant No. ZF4562901GM8. Y1 - 2020 U6 - https://doi.org/10.1116/1.5139316 VL - 38 IS - 2 PB - AIP Publishing ER - TY - JOUR A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Simulation and Fabrication of Silicon Field Emission Cathodes for Cold Electron Sources JF - Advanced Materials Research N2 - We report on the simulation and fabrication of nanostructured silicon surfaces for field emission (FE) applications, e.g. ionization sensors and x-ray tubes. For the design and optimization of field-emitting silicon structures, the influence of the geometric parameters like tip height, apex radius, aperture angle and curvature shape on the field enhancement factor was investigated by simulation using finite element method. A universal geometric model which describes the real geometry of our silicon structures sufficiently accurate was taken for modeling a variety of different silicon tip structures as well as ridge structures. While a high dependency of the field enhancement on the aspect ratio and the aperture angle was found, the simulations show that the elliptic curvature affects the field enhancement only marginally. Finally, an improved process for fabrication of such silicon structures on n-type as well as p-type substrate is described, using reactive ion etching with adjustable anisotropy, wet thermal oxidation and wet etching. KW - field emission cathodes KW - field enhancement factor KW - silicon field emitter Y1 - 2014 U6 - https://doi.org/10.4028/www.scientific.net/amr.1024.48 VL - 1024 SP - 48 EP - 51 ER - TY - JOUR A1 - Ławrowski, Robert Damian A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Field emission arrays from graphite fabricated by laser micromachining JF - Journal of Vacuum Science & Technology B N2 - Laser micro structuring allows the manufacturing of conical shaped emitters on a graphitized carbon substrate without any additional treatment. Integral field emission measurements were performed in a diode configuration with a 50 µm mica spacer and a metalized Si-grid in a vacuum chamber at pressures of about 10-9 mbar. Emission currents up to 10 µA at a voltage of 1000 V (11 MV/m) with a positive current drift were observed for an array of 16 emitters. A strong modification of the emitter tip is noticeable after individual measurements. A comparable alteration of the surface is also achieved by an electrochemical treatment of the samples with a potassium hydroxide solution. However, the IV-measurements of such samples show higher onset voltages, but also higher integral emission currents. For all arrays an ideal FN behaviour is only noticeable at applied voltages below 625 V (7 MV/m). Numerical calculations indicate that the deviation in the FN-plot for higher voltage values is caused by the change of the effective work function. Y1 - 2022 U6 - https://doi.org/10.1116/6.0001547 VL - 40 IS - 2 PB - AIP Publishing ER - TY - JOUR A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Improvement of Homogenity and Aspect Ratio of Silicon Tips for Field Emission by Reactive-Ion Etching JF - Advances in materials science and engineering N2 - The homogeneity of emitters is very important for the performance of field emission (FE) devices. Reactive-ion etching (RIE) and oxidation have significant influences on the geometry of silicon tips. The RIE influences mainly the anisotropy of the emitters. Pressure has a strong impact on the anisotropic factor. Reducing the pressure results in a higher anisotropy, but the etch rate is also lower. A longer time of etching compensates this effect. Furthermore an improvement of homogeneity was observed. The impact of uprating is quite low for the anisotropic factor, but significant for the homogeneity. At low power the height and undercut of the emitters are more constant over the whole wafer. The oxidation itself is very homogeneous and has no observable effect on further variation of the homogeneity. This modified fabrication process allows solving the problem of inhomogeneity of previous field emission arrays. Y1 - 2014 U6 - https://doi.org/10.1155/2014/948708 VL - 2014 PB - Hindawi ER - TY - GEN A1 - Bieker, Johannes A1 - Schlaak, Helmut F. A1 - Wilfert, Stefan A1 - Ławrowski, Robert Damian A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Development of FE-based electron sources for XHVion gauges in cryogenic vacuum environments T2 - 32nd International Vacuum Nanoelectronics Conference (IVNC 2019), 22.-26.07.2019, Cincinnati, USA Y1 - 2019 ER - TY - GEN A1 - Ławrowski, Robert Damian A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Individually Addressable Silicon Field Emission Cathodes Fabricated by Laser Micromachining T2 - 7th ITG International Vacuum Electronics Workshop (IVEW) 2020 and 13th International Vacuum Electron Sources Conference (IVeSC) 2020, 26. - 29.5.2020, Bad Honnef Y1 - 2020 ER - TY - GEN A1 - Hausladen, Matthias A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Fast Pulse Source for Field Emission Applications T2 - 7th ITG International Vacuum Electronics Workshop (IVEW) 2020 and 13th International Vacuum Electron Sources Conference (IVeSC) 2020, 26. - 29.5.2020, Bad Honnef Y1 - 2020 ER - TY - CHAP A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Muller, F. A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Serbun, Pavel A1 - Müller, Günter T1 - Comparison of integral and local field-emission properties of Mo-coated p-Si tip arrays T2 - 2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China N2 - Silicon tip arrays were fabricated by means of reactive ion etching followed by oxidation for final sharpening and molybdenum thin film coating. The field-emission (FE) properties of these Mo-coated p-Si tip arrays were systemically investigated by different measurement techniques. Integral measurements in diode configuration yielded a turn-on field (for 1 nA) of 22 V/μm and nearly stable FE currents up to 6.6 μA at 38 V/μm. The effective field enhancements factor extracted from the FN plots is about 180. Detailed investigations of these FE arrays were also performed by means of field emission scanning microscopy combined with electron microscopy. A rather limited efficiency of the tips (50% at 1500 V) and FE homogeneity (180 nA at 700 V) might be correlated with the varying morphology of the tips and the presence of oxides. Local I-V measurements of selected single tips revealed both activation and deactivation effects, which finally resulted in nearly reproducible I-V curves. Current stability measurements at a constant voltage showed rather large fluctuations (0.1-1 μA) of the FE current, which could be reduced up to 1.7% by using of a PID-regulated voltage source. SEM images showed unchanged tip shape after the current processing. KW - CATHODES KW - Coatings KW - Current measurement KW - field emission KW - Iron KW - Mo-coated KW - p-Si tip KW - Scanning electron microscopy KW - silicon KW - tip arrays KW - Vacuum technology Y1 - 2015 U6 - https://doi.org/10.1109/IVNC.2015.7225579 SP - 192 EP - 193 PB - IEEE ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Dams, Florian A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Fabrication and simulation of silicon structures with high aspect ratio for field emission devices T2 - 2014 27th International Vacuum Nanoelectronics Conference (IVNC), 6-10 July 2014, Engelberg, Switzerland N2 - To obtain higher field enhancement factors of Si-tip structures, we present an improved fabrication process utilizing reactive-ion etching (RIE) with an inductively coupled plasma (ICP). In our design, a pillar under the tips is realized by a combination of RIE with ICP. With adjusted power settings (≈ 240 W) and step times (<; 5 s), vertical slopes with a low roughness of approximately 10 nm to 20 nm are possible. The remaining silicon is oxidized thermally to sharpen the emitters. A final tip radius of R <; 20 nm is obtained for the tips of the emitters. The pillar height HP can be mainly adjusted by the duration of the ICP-etching step. A total emitter height of H ≈ 6 μm with a pillar height of HP ≈ 5 μm is achieved. Simulations with COMSOL Multiphysics® are applied to calculate the field enhancement factor β. A two-dimensional model is used in rotational symmetry. In addition to the previous model, a pillar with a varying diameter ØP and height HP is added. A conventional emitter (H = 1 μm and R = 20 nm) placed on a pillar of the height HP ≈ 5 μm approximately results in a three times higher β-factor (β≈ 105). By decreasing the diameter ØP a slight increase of the β-factor is observed. However, the aspect ratio of the emitter mainly influences on the β-factor. KW - Anodes KW - CATHODES KW - FABRICATION KW - field emission KW - field emitter array KW - field enhancement factor KW - Iterative closest point algorithm KW - Lead KW - silicon tips Y1 - 2014 U6 - https://doi.org/10.1109/IVNC.2014.6894805 SP - 193 EP - 194 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Ławrowski, Robert Damian T1 - Gated p-Si field emitter arrays for sensor applications T2 - 2015 28th International Vacuum Nanoelectronics Conference (IVNC) N2 - We report on gated p-type Si-tip array cathodes for implementation into field emission electron sources for sensor applications. Arrays of 16 and 100 tips with tip heights of 3 μm and tip radii below 30 nm with integrated gate electrodes concentrically positioned 2 μm below the tip apexes were fabricated using an improved process, which leads to an enhanced isolation layer quality with sufficient breakdown field strengths and low leakage currents. Integral measurements with a fixed grid potential of 400 V showed emission currents up to 35 μA for 100 tips at a cathode voltage of 150 V and an almost negligible parasitic gate current. The array with 16 p-type Si-tips showed a significant stabilization of the emission current in the range of 0.3 - 0.4 μA, for cathode voltages between 90 V and 150 V. The current fluctuation in this saturation regime was measured for 10 minutes and a value of less than ± 1% was observed. No degradation of the cathode was found after 6 hours of operation at a constant cathode voltage of 100 V and a constant grid voltage of 400 V. KW - CATHODES KW - Current measurement KW - Current stabilization KW - field emission KW - integrated gate-electrode KW - Iron KW - Logic gates KW - semiconductor KW - Semiconductor device measurement KW - silicon KW - silicon tip array Y1 - 2015 U6 - https://doi.org/10.1109/IVNC.2015.7225567 SP - 164 EP - 165 PB - IEEE ER - TY - CHAP A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Müller, F. A1 - Schreiner, Rupert A1 - Serbun, Pavel A1 - Müller, Günter T1 - Enhanced field emission from p-doped black silicon on pillar structures T2 - 2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China N2 - Aligned square arrays of black silicon (b-Si) on top of pillars were fabricated on p-type silicon substrate by a deep-etching step combined with a b-Si process. Two 10×10 arrays with pillar heights of 8 μm and 20 μm and one b-Si reference sample without pillars were investigated. Integral field emission (FE) measurements of the arrays yielded rather low onset-fields between 6.4 V/μm and 13.5 V/μm and field enhancement factors between 430 and 800. The I-V curves showed typical Fowler-Nordheim behavior for low fields, whereas a saturation region was observed at higher fields. The maximum integral current in the saturation region was 8 μA at a field of 20 V/μm. The stability of the emission current was investigated over 3 hours and revealed moderate fluctuations of ± 8% in the saturation region. Voltage scans showed well-aligned FE from nearly all pillars. KW - black silicon KW - CATHODES KW - Current measurement KW - Etching KW - FABRICATION KW - field emission KW - field emitter array KW - Iron KW - silicon KW - Vacuum technology Y1 - 2015 U6 - https://doi.org/10.1109/IVNC.2015.7225547 SP - 104 EP - 105 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Realisierung von Siliziumspitzenarrays mit integrierter Gate-Elektrode für Anwendungen in der Vakuumsensorik T2 - 4. Landshuter Symposium Mikrosystemtechnik, Mikrosystemtechnik als Schlüsseltechnologie der Systemintegration, Tagungsband zum Symposium 12./13. März 2014, Hochschule Landshut N2 - Bei der Feldemission (kalte Emission) können Elektronen durch ein starkes elektrisches Feld eine glatte und leitende Oberfläche verlassen. Die Elektronen tunneln dabei durch eine Potentialbarriere, deren Breite durch ein äußeres elektrisches Feld verkleinert wird. Durch das Hinzufügen einer integrierten Gate-Elektrode um eine Siliziumspitze kann die notwendige Einsatzspannung für Feldemission deutlich gesenkt werden. Zwischen Si-Kathode und Gate-Elektrode befindet sich dabei eine Isolationsschicht, die höchste Anforderungen bezüglich der elektrischen Durchbruchsfestigkeit erfüllen muss. Mit einer Kombination aus Trocken- (Schichtdicke 50 nm) und Feuchtoxid (Schichtdicke 950 nm) konnte eine Isolationsschicht entwickelt werden, die im integrierten Aufbau eine minimale Durchbruchsfeldstärke von 3,2 MV/cm aufweist. Für die Realisierung von Siliziumkathoden mit integrierter Gate-Elektrode wurde ein bereits bestehender Herstellungsprozess um zusätzliche Prozessschritte erweitert. Die Übertragung der lateralen Position der Spitze erfolgt durch Strukturierung des Umkehrlacks AZ5214 und einer RIE-Ätzung der zuvor hergestellten SiO2-Schicht. Nach dem Entfernen der Lackschicht wird die vertikale Struktur der Siliziumspitzen durch einen RIE-Ätzprozess mit den Prozessgasen SF6 und O)2 realisiert. Aus einer thermischen Oxidation bei 940 °C resultiert anschließend die Isolationsschicht zwischen Si-Kathode und Gate-Elektrode . Gleichzeitig wird diese Anschärfeoxidation auch zur Realisierung der endgültigen Spitzengeometrie verwendet. Durch die lithographische Strukturierung des Photolacks AZ5214 kann dabei die Fläche der aufgedampften Gate-Elektrode festgelegt werden. Die Gate-Elektrode wird in einem selbstjustierenden Prozessschritt exakt konzentrisch um die Si-Spitze aufgedampft. Der gerichtete Aufdampfprozess bewirkt eine Abschattung, so dass das Oxidplättchen nicht komplett von Metall ummantelt wird. Die Opferschicht aus Photolack wird mit den nicht benötigten Metallflächen in einem Lift-off-Prozess entfernt. KW - elektrischer Durchbruch KW - Feldelektronenemission KW - Halbleiterschicht KW - Isolierschicht KW - Kathode KW - Silicium KW - Vakuumsensor Y1 - 2014 SN - 978-3-9812696-5-9 SP - 36 EP - 41 CY - Landshut ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Dams, Florian A1 - Serbun, Pavel A1 - Müller, Günter A1 - Schreiner, Rupert T1 - Spitzen- und Kantenemitter aus Silizium mit einem hohen Aspektverhältnis für Ionisationsgassensoren T2 - Mikrosystemtechnik als Schlüsseltechnologie der Systemintegration : 4. Landshuter Symposium Mikrosystemtechnik ; Tagungsband zum Symposium ; 12./13. März 2014, Hochschule Landshut N2 - Durch die Optimierung von reaktivem Ionenätzen mit induktiv gekoppeltem Plasma ist die Herstellung von verschiedenen Siliziumkathoden mit hoher Anisotropie und hohem Aspektverhältnis für Feldemissionsanwendungen möglich. Simulationen mit COMSOL Multiphysics untermauern das Potential von solchen Spitzen- und Kantenfeldemittern. Die Ergebnisse der Simulation zeigen einen zwei- bis sechsfach höheren Feldüberhöhungsfaktor der tiefgeätzten Strukturen im Vergleich zu identischen Emittern ohne zusätzliche Tiefenätzung. Feldemissionsmessungen bestätigen die Simulationsergebnisse. Der modifizierte Herstellungsprozess der Feldemitter ermöglicht somit einen zuverlässigen Betrieb von Feldemissionselektronenquellen bei kleineren makroskopischen Feldstärken. Außerdem weisen die Messungen des Emissionsstroms im Sättigungsbereich eine weitgehende Unabhängigkeit vom elektrischen Feld auf. Lokale Feldemissionsmessungen ergeben dadurch eine deutliche Stromstabilisierung, welche über große Feldstärkenbereiche konstant bleibt. Die Nutzung der HAR-Emitter (high aspect ratio) ist damit eine gute Voraussetzung für einen zuverlässigen Betrieb der Emissionskathoden bei kleinen Feldstärken für die Anwendung in Ionisationsgassensoren. KW - Emitter KW - Feldelektronenemission KW - Gassensor KW - Herstellung KW - Ionenemission KW - Silicium Y1 - 2014 SN - 978-3-9812696-5-9 SP - 28 EP - 35 PB - Cluster Mikrosystemtechnik CY - Landshut ER - TY - JOUR A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Improvement of Homogeneity and Aspect Ratio of Silicon Tips for Field Emission by Reactive-Ion Etching JF - Advances in Materials Science and Engineering. Special issue: Advances in Smart Materials and Applications N2 - The homogeneity of emitters is very important for the performance of field emission (FE) devices. Reactive-ion etching (RIE) and oxidation have significant influences on the geometry of silicon tips. The RIE influences mainly the anisotropy of the emitters. Pressure has a strong impact on the anisotropic factor. Reducing the pressure results in a higher anisotropy, but the etch rate is also lower. A longer time of etching compensates this effect. Furthermore an improvement of homogeneity was observed. The impact of uprating is quite low for the anisotropic factor, but significant for the homogeneity. At low power the height and undercut of the emitters are more constant over the whole wafer. The oxidation itself is very homogeneous and has no observable effect on further variation of the homogeneity. This modified fabrication process allows solving the problem of inhomogeneity of previous field emission arrays. Y1 - 2014 U6 - https://doi.org/10.1155/2014/948708 SN - 1687-8442 SN - 1687-8434 VL - 2014 SP - 1 EP - 6 PB - Hindawi ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Influence of reactive ion etching parameters on the geometry of silicon tip cathodes for field emission T2 - Applied Research Conference 2013, ARC 2013 : 17th and 18th October 2013, Deggendorf Y1 - 2013 SN - 978-3-8440-2274-2 SP - 67 EP - 69 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Feldemissionselektronenquellen basierend auf Siliziumemittern mit hohen Aspektverhältnis T2 - Forschungsbericht der OTH Regensburg 2013 Y1 - 2013 UR - https://doi.org/10.35096/othr/pub-799 SP - 47 EP - 48 CY - Regensburg ER - TY - JOUR A1 - Lindner, Matthias A1 - Pipa, Andrei V. A1 - Brandenburg, Ronny A1 - Schreiner, Rupert T1 - Expansion of surface barrier discharge scrutinized JF - Plasma Sources Science and Technology N2 - Developing the fundamentals for the electrical diagnostics of surface dielectric barrier discharges (SDBDs) is of enormous importance for several applications, for example, flow control and gas cleaning. The main challenge is to account for the discharge expansion along the dielectric surface. Typically, a linear expansion with the amplitude of the applied voltage is observed. In this work, we report on a step-wise SDBD expansion along the Al 2 O 3 dielectric surface. More specific, the discharge occupied a certain area after ignition, which remained constant until the voltage exceeded the critical amplitude V L . This absence of expansion is seen as a linear dependence of the discharge power on the applied voltage and it was additionally confirmed by photographs with long exposure times. This novel phenomenon is more pronounced for thicker dielectrics. It is suggested that the derivative of the charge-voltage characteristics can be used for the determination of all essential parameters of the simplest equivalent circuit of SDBDs. Moreover, it was shown that the derivative of the charge-voltage characteristics for the positive half-cycle of the discharge agrees numerically with the voltage dependence of the reactor capacitance derived from photographs. This agreement between both measurement methods indicates a similar step-wise expansion of the SDBD even if a voltage amplitude above V L is applied. … Y1 - 2022 U6 - https://doi.org/10.1088/1361-6595/ac95bf VL - 31 IS - 10 PB - IOP Publishing ER - TY - CHAP A1 - Mingels, Stephan A1 - Bornmann, Benjamin A1 - Lützenkirchen-Hecht, Dirk A1 - Müller, Günter A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Schreiner, Rupert ED - Scholl, Caitlin ED - Schaa, Volker R.W. T1 - Electric Field Dependence of Photoemission from n- and p-type Si Crystals T2 - Proceedings, 35th International Free Electron Laser Conference (FEL 2013) : New York, NY, USA, August 26-19, 2013 N2 - The performance of free electron lasers depends on the brilliance of the electron source. Nowadays photo-cathodes (e.g. Cs2Te) are used despite of their high emittance. To develop robust and more brilliant cathodes we have built up an UHV system which enables systematic photoemission (PE) measurements with a tunable pulsed laser (hv) at high electric fields (E). First results on Au and Ag crystals revealed only low quantum efficiency (QE) due to fast electron relaxation. Hence, we have started QE(hv,E) investigations on n- and p-Si wafers. Resonant PE was observed above as well as below the work function O, which can be assigned to optical transitions in the electronic band structure or explained by thermally excited states at the bottom of the conduction band. As expected, only low QE values were achieved even for n-Si probably due to surface oxide. Moreover, a significant rise of the QE peaks above O were obtained for n-Si at E >8 MV/m but limited by the occurrence of parasitic field emission from dust particles. Y1 - 2013 UR - https://accelconf.web.cern.ch/FEL2013/papers/tupso49.pdf#search=%20domain%3Daccelconf%2Eweb%2Ecern%2Ech%20%20%2Bauthor%3A%22schreiner%22%20%20url%3Aaccelconf%2FFEL2013%20FileExtension%3Dpdf%20%2Durl%3Aabstract%20%2Durl%3Aaccelconf%2Fjacow SN - 9783954501267 SP - 339 EP - 343 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Schreiner, Rupert A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Serbun, Pavel A1 - Bornmann, Benjamin A1 - Navitski, Aliaksandr A1 - Müller, Günter T1 - Highly uniform and stable electron field emission from B-doped Si-tip arrays for applications in integrated vacuum microelectronic devices T2 - 25th International Vacuum Nanoelectronics Conference (IVNC) - Jeju, Korea (South), 09.07. - 13.07.2012 N2 - In order to improve the uniformity and field emission stability of p-type silicon tip arrays for pulsed sensor applications, we have systematically studied the influence of the fabrication parameters on the tip shape and the specific operating conditions. Based on detailed design calculations of the field enhancement, we have fabricated a series of hexagonal arrays of B-doped Si-tips in a triangular arrangement, each containing a different number of tips (91, 575 and 1300) of 1 μm height, 20 nm apex radius, and 20 μm pitch. The field emission properties of both individual tips and complete arrays were investigated with by field emission scanning microscopy. The current plateaus of these tips typically occur at about 10 nA and 60 V/μm field level. In this carrier depletion range, single tips provide the highest current stability (<; 4%) and optical current switching ratios of ~2.5. Rather homogeneous emission of the tip arrays leads to an almost linear scaling of the saturation current (2 nA/tip) and to a much improved current stability (<; 1%) measured over 1 hour. KW - boron KW - circuit stability KW - elemental semiconductors KW - field emission ion microscopy KW - field emitter arrays KW - integrated optoelectronics KW - microfabrication KW - microsensors KW - optical switches KW - silicon tips Y1 - 2012 SN - 978-1-4673-1984-3 SN - 978-1-4673-1983-6 SN - 978-1-4673-1982-9 U6 - https://doi.org/10.1109/IVNC.2012.6316857 SN - 2380-6311 SN - 2164-2370 SP - 1 EP - 2 PB - IEEE CY - Piscataway, NJ. ER - TY - CHAP A1 - Schreiner, Rupert A1 - Dams, Florian A1 - Prommesberger, Christian A1 - Bornmann, Benjamin A1 - Serbun, Pavel A1 - Navitski, Aliaksandr A1 - Müller, Günter T1 - Silicon-based integrated field emission electron sources for sensor application T2 - 24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Wuppertal, Germany N2 - We report on the design, fabrication and characterization of p-type silicon field emitter arrays for the application in compact fast switchable electron sources. Since standard silicon technology has been used to prepare the devices, they can be easily integrated with other silicon based sensors and electronic components, too. The emitter arrays consist of approx. 3×105 tips per cm2, with a tip radius less than 20 nm. By using self-aligned processes, an integrated gate electrode with a diameter of  3 μm was placed concentrically around the tips. A mesh of silicon-beams with a grating period of 100 μm and beam width of 20 μm forms the anode of the electron source. A glass wafer (thickness 300 μm) acts as spacer between anode and Si-tip cathode. Characterization of the field emission properties of the emitter arrays was performed by high resolution field emission scanning microscopy. The emitter arrays exhibit a highly stable and very homogeneous emission. A maximum stable current of 0.1 μA per tip was found. A saturation level in the voltage current characteristics, which was found at around 10 nA, supports current stabilisation and will enable optical modulation of the emission current. KW - anodes KW - cathodes KW - field emission electron microscopy KW - field emission electron sources KW - field emitter arrays KW - silicon tips KW - structured cold cathode KW - vacuum sensors Y1 - 2012 UR - https://ieeexplore.ieee.org/document/6004541?arnumber=6004541 SP - 19 EP - 20 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Bornmann, Benjamin A1 - Mingels, Stephan A1 - Serbun, Pavel A1 - Lützenkirchen-Hecht, Dirk A1 - Müller, Günter A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Photosensitivity of electron field emission from B-doped Si-tip arrays T2 - 25th International Vacuum Nanoelectronics Conference (IVNC) ; Jeju, Korea (South), 09.07.2012 - 13.07.2012 N2 - The electron current from field-emitting B-doped Si-tip arrays under illumination was studied. An improved cathode design with a patch of 271 tips yielded a reproducible cathode current between 0.2-2000 nA in the electric field range of 3.8-6.6 V/μm. The plateau in the Fowler-Nordheim plot shows the actual carrier depletion and leads to a very stable emission at ~1 μA with a current noise of less than 3.3 %. Color-filtered halogen lamp illumination was used to investigate the photo-sensitivity of the saturation current. The intensity-normalized current switching ratio increases nonlinearly with the photon energy. This hints either for secondary generation in the conduction band or deeper valence band excitation. The first is supported by a rough estimation of the quantum efficiency. Further experiments with a tunable laser and electron spectroscopy are planned. KW - boron KW - electron field emission KW - electron spectroscopy KW - elemental semiconductors KW - field emitter arrays KW - halogens KW - lamps KW - lighting KW - p-doped Si tips KW - photosensitivity KW - silicon KW - valence bands Y1 - 2012 SN - 978-1-4673-1984-3 SN - 978-1-4673-1983-6 SN - 978-1-4673-1982-9 U6 - https://doi.org/10.1109/IVNC.2012.6316980 SN - 2380-6311 SN - 2164-2370 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Dams, Florian A1 - Serbun, Pavel A1 - Bornmann, Benjamin A1 - Mingels, Stephan A1 - Müller, Günter A1 - Schreiner, Rupert T1 - Si-Feldemissionskathoden für Anwendungen in miniaturisierten Ionisationsvakuumsensoren T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft e.V. (DPG), Regensburg, 10. - 15. März 2013 N2 - Feldemissionselektronenquellen sind aufgrund ihrer prinzipiellen Vorteile gegenüber Glühkathoden bereits seit längerer Zeit Gegenstand der Forschung und werden bisher nur in einigen Spezialanwendungen erfolgreich eingesetzt. Hierbei werden Einzelspitzen mit Spannungen im kV-Bereich und Strömen im nA-Bereich betrieben. Dagegen werden für miniaturisierte Sensorsysteme eher Spannungen von ca. 100 V und Ströme von ca. 1 mA benötigt. Dazu wurden bisher meist Feldemissionskathoden mit CNTs vorgeschlagen, welche für Anwendungen in der Halbleiterindustrie aufgrund des Kohlenstoffanteils nicht erwünscht sind. Ziel unserer Arbeit ist es, Si-basierte Elektronenquellen zu realisieren, die mit anderen miniaturisierten Vakuumsensoren auf einem Chip integrierbar sind. Mithilfe eines optimierten Herstellungsprozesses konnten wir p-Si-Spitzenarrays mit Spitzenradien von wenigen nm realisieren [1]. Messungen an diesen Strukturen zeigen ein sehr homogenes Emissionsverhalten, das vor allem im Sättigungsbereich bei Emissionsströmen von ca. 10 nA pro Spitze zeitlich stabil (Schwankungen < 5 %) und optisch schaltbar (Faktor > 2.5) ist [2]. Y1 - 2013 UR - https://www.researchgate.net/publication/281373011_Si-Feldemissionskathoden_fur_Anwendungen_in_miniaturisierten_Ionisationsvakuumsensoren PB - Deutsche Physikalische Gesellschaft e.V. ER - TY - JOUR A1 - Bornmann, Benjamin A1 - Mingels, Stephan A1 - Dams, Florian A1 - Prommesberger, Christian A1 - Schreiner, Rupert A1 - Lützenkirchen-Hecht, Dirk A1 - Müller, Günter T1 - Electron spectrometer in adjustable triode configuration for photo-induced field emission measurements JF - The Review of scientific instruments N2 - We have constructed a new ultrahigh vacuum apparatus with a triode configuration for the systematic investigation of photo-induced field emission (PFE) from metallic or semiconducting cathodes. These are exposed to electric fields up to 400 MV∕m and laser irradiation by means of hole or mesh gates. Cathodes and gates are in situ exchangeable and adjustable with high precision to ensure a homogeneous extraction of electrons which are partially transmitted to the fixed electron spectrometer. Its hemispherical sector analyzer provides an energy resolution limit of 8 meV. The commissioning of the measurement system has been performed with a tungsten needle. Its temperature showed up in the high-energy tail of the electron spectrum, while its work function was derived from the spectral low-energy part combined with the integral current-voltage curve. First PFE measurements on B-doped Si-tip arrays yielded a small field emission current increase under green laser illumination. A shift and splitting of the energy spectra was observed which revealed different emission regimes as well as the photosensitivity of the cathode due to carrier excitation into the conduction band. For the full exploitation of the PFE system, a tunable laser over a wide eV-range is required. Y1 - 2012 U6 - https://doi.org/10.1063/1.3673475 VL - 83 IS - 1 PB - American Institute of Physics CY - Melville, NY ER - TY - CHAP A1 - Bornmann, Benjamin A1 - Mingels, Stephan A1 - Lützenkirchen-Hecht, Dirk A1 - Müller, Günter A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Field emission spectroscopy studies on photo-sensitive p-doped Si-tip arrays T2 - 24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Historische Stadthalle Wuppertal, Germany N2 - The influence of laser illumination on the integral as well as on the energy-resolved electron currents from well-defined p-doped Si-tip arrays was investigated. First results have provided stable cathode currents between 100 nA and 500 μA in a field range of 2-20 V/μm. Green laser illumination resulted in an enhanced cathode current and an increased population of the conduction band which can be seen in the spectra. Charging of the cathode surface, however, leads to a shift and broadening of the spectra which complicate their analysis. Therefore, further experiments with a rotatable cathode and a varying number of tips as well as with a tunable laser are planned. KW - cathodes KW - conduction bands KW - electron field emission KW - elemental semiconductors KW - field emission spectroscopy KW - field emitter arrays KW - laser illumination KW - lighting KW - p-doped silicon tips KW - photo sensitivity KW - silicon Y1 - 2011 UR - https://ieeexplore.ieee.org/document/6004582?arnumber=6004582 SN - 978-3-00-035081-8 SN - 978-1-4577-1243-2 SN - 2380-6311 SN - 2164-2370 SP - 101 EP - 102 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Dams, Florian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Rutkowski, S. A1 - Bornmann, Benjamin A1 - Müller, Günter T1 - Simulation of electron trajectories of a field emission electron source in triode configuration by using finite element methods T2 - 24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Historische Stadthalle Wuppertal, Germany N2 - The finite element simulation program COMSOL Multiphysics® was used to simulate the emission efficiency of a silicon tip electron source in triode configuration for different geometries and electrode potentials. The simulation predicts a maximum emission efficiency of 84% for an optimized structure. In a second simulation a gate electrode was concentrically arranged above a single CNT column. Here, the efficiency was simulated as a function of gate hole geometry, electrode potentials and distances between the electrodes. The simulation shows that a conical shape of the gate hole results in an efficiency up to nearly 100%. KW - carbon nanotubes KW - electron field emission KW - electron source simulation KW - finite element analysis KW - simulation of electron trajectories KW - triodes Y1 - 2011 UR - https://ieeexplore.ieee.org/document/6004589 SN - 978-3-00-035081-8 SN - 978-1-4577-1243-2 SN - 2380-6311 SN - 2164-2370 SP - 144 EP - 145 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Weber, Karsten A1 - Dendorfer, Sebastian A1 - Süß, Franz A1 - Kubowitsch, Simone A1 - Schratzenstaller, Thomas A1 - Haug, Sonja A1 - Mohr, Christa A1 - Kiesl, Hans A1 - Drechsler, Jörg A1 - Westner, Markus A1 - Kobus, Jörn A1 - Schubert, Martin J. W. A1 - Zenger, Stefan A1 - Pietsch, Alexander A1 - Weiß, Josef A1 - Hinterseer, Sebastian A1 - Schieck, Roland A1 - Scherzinger, Stefanie A1 - Klettke, Meike A1 - Ringlstetter, Andreas A1 - Störl, Uta A1 - Bissyandé, Tegawendé F. A1 - Seeburger, Achim A1 - Schindler, Timo A1 - Ramsauer, Ralf A1 - Kiszka, Jan A1 - Kölbl, Andreas A1 - Lohmann, Daniel A1 - Mauerer, Wolfgang A1 - Maier, Johannes A1 - Scorna, Ulrike A1 - Palm, Christoph A1 - Soska, Alexander A1 - Mottok, Jürgen A1 - Ellermeier, Andreas A1 - Vögele, Daniel A1 - Hierl, Stefan A1 - Briem, Ulrich A1 - Buschmann, Knut A1 - Ehrlich, Ingo A1 - Pongratz, Christian A1 - Pielmeier, Benjamin A1 - Tyroller, Quirin A1 - Monkman, Gareth J. A1 - Gut, Franz A1 - Roth, Carina A1 - Hausler, Peter A1 - Bierl, Rudolf A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Huang, Yifeng A1 - She, Juncong A1 - Ottl, Andreas A1 - Rieger, Walter A1 - Kraml, Agnes A1 - Poxleitner, Thomas A1 - Hofer, Simon A1 - Heisterkamp, Benjamin A1 - Lerch, Maximilian A1 - Sammer, Nike A1 - Golde, Olivia A1 - Wellnitz, Felix A1 - Schmid, Sandra A1 - Muntschick, Claudia A1 - Kusterle, Wolfgang A1 - Paric, Ivan A1 - Brückl, Oliver A1 - Haslbeck, Matthias A1 - Schmidt, Ottfried A1 - Schwanzer, Peter A1 - Rabl, Hans-Peter A1 - Sterner, Michael A1 - Bauer, Franz A1 - Steinmann, Sven A1 - Eckert, Fabian A1 - Hofrichter, Andreas ED - Baier, Wolfgang T1 - Forschungsbericht 2017 T3 - Forschungsberichte der OTH Regensburg - 2017 KW - Forschung KW - Forschungsbericht Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-13835 SN - 978-3-9818209-3-5 CY - Regensburg ER - TY - CHAP A1 - Bachmann, Michael A1 - Dams, Florian A1 - Düsberg, F. A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Stability investigation of high aspect ratio n-type silicon field emitter arrays T2 - 2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China N2 - Electron sources based on silicon field emitter arrays, produced in processes based on semiconductor technology, are good candidates for a miniaturized X-ray source. A key parameter for this application is the stability of the X-ray photon flux and, thus, the emission current. In the present work we have investigated the influence of the residual gas pressure and a resistor in series on the emission stability of a high aspect ratio n-type silicon emitter array with hybrid extraction electrode. An increase of current fluctuations was found for pressures above 10-6 mbar. High resistances in series to the emitter array alter the emission characteristics, but greatly suppress spikes in the emission current and improve its stability. This, however, strongly depends on the bias point. The field enhancement factor is not affected by the resistance. In a long term measurement the emission current was found to be constant after an initial phase of degradation. KW - Current measurement KW - emission current stability KW - field emitter array KW - Field emitter arrays KW - RESISTANCE KW - Resistors KW - semiconductor field emission KW - silicon KW - silicon tips KW - Stability analysis KW - Thermal stability KW - XRF spectroscopy Y1 - 2015 U6 - https://doi.org/10.1109/IVNC.2015.7225584 SP - 204 EP - 205 PB - IEEE ER - TY - CHAP A1 - Serbun, Pavel A1 - Navitski, Aliaksandr A1 - Müller, Günter A1 - Schreiner, Rupert A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian T1 - Scaling of the field emission current from B-doped Si-tip arrays T2 - 25th International Vacuum Nanoelectronics Conference (IVNC) ; Jeju, Korea (South), 09.07.2012 - 13.07.2012 N2 - We have fabricated a test chip with various hexagonal arrays of B-doped Si tips (height ~ 3 μm, apex radius <; 30 nm, number 1-4447, resistivity 4 Ωcm, 100 orientation) in triangular arrangement (pitch 10 μm, density 1.16×10 6 cm -2 ) in order to systematically investigate the field emission current scaling with the number N of tips. Regulated voltage scans for 1 nA revealed rather efficient emission from nearly all tips of the arrays at an average field of 15 V/μm. The expected current plateau was always obtained at fields around 20 V/μm, but its width strongly increased with N. In this carrier depletion range, the single tip provided a much higher stability (<; 5%) of the current (2-3 nA) than at lower (>; 50 %) and higher currents (>; 30%). Integral current measurements of the hexagonal arrays resulted in a statistically improved current stability (<; 1%) but only a weak increase of the total current with N 0.28 yet. These results will be discussed with respect to the remaining inhomogeneity of the tips. KW - Anodes KW - B-doped KW - boron KW - Current measurement KW - current scaling KW - electron field emission KW - elemental semiconductors KW - field emitter arrays KW - Iron KW - Nonhomogeneous media KW - silicon KW - Voltage control Y1 - 2012 SN - 978-1-4673-1984-3 SN - 978-1-4673-1983-6 SN - 978-1-4673-1982-9 U6 - https://doi.org/10.1109/IVNC.2012.6316965 SN - 2380-6311 SN - 2164-2370 SP - 1 EP - 2 PB - IEEE CY - Piscataway, N.J. ER - TY - JOUR A1 - Ławrowski, Robert Damian A1 - Pirker, Luka A1 - Kaneko, Keita A1 - Kokubo, Hiroki A1 - Bachmann, Michael A1 - Ikuno, Takashi A1 - Remskar, Maja A1 - Schreiner, Rupert T1 - Field emission from nanotubes and flakes of transition metal dichalcogenides JF - Journal of Vacuum Science and Technology B N2 - Transition metal dichalcogenides such as MoS2 and WS2 are low-dimensional semiconductor materials. MoS2 and WS2 nanotubes and flakes were grown by a chemical transport reaction under a temperature gradient. I2 was used as a transport agent for previously synthesized MoS2 and WS2, respectively. These multilayered nanotubes are indirect bandgap semiconductors with a bandgap depending on their diameter. WS2 flakes were prepared by the sulfurization of thin WOx flakes. To increase the field enhancement of such low-dimensional structures by a higher aspect ratio, two approaches were examined: (a) the MoS2 and WS2 nanotubes were attached individually by a focused ion beam with Pt on dry etched n-type Si pillars and (b) the WS2 flakes were grown directly on the surface of the (n-type and p-type) Si pillars. Integral field emission measurements were performed in a diode configuration with a 50 μm mica spacer in a vacuum chamber at pressures of about 10−9 mbar. At a voltage of 900 V (18 MV/m), the integral emission current from the nanotubes is up to 11 μA for the lateral mounted MoS2 and about 1.3 μA (1.0 μA) for the upright mounted WS2 (MoS2). The onset voltage for a current of 1 nA is about 550 V for MoS2 and 500 V for WS2, respectively. The voltage conversion factor is in the range of 6 × 104–8 × 104 cm−1 for the nanotubes. The mounted MoS2 flakes show a field emission current of about 6 μA at 18 MV/m in contrast to the directly grown WS2 flakes, which show a pronounced saturation regime and, therefore, a lower emission current of about 0.5 μA is reached at 1500 V (25 MV/m). The WS2 flakes show a two times higher (1 × 105 cm−1) voltage conversion factor in comparison to the MoS2 flakes (5 × 104 cm−1). The extracted characteristics of the current-limiting part show a difference in the behavior of the extracted current-limiting characteristics between the lateral (linear) and upright mounted (exponential) nanotubes and the MoS2 flakes. In contrast, the WS2 flakes show charge carrier depletion effects. Y1 - 2020 U6 - https://doi.org/10.1116/1.5140474 VL - 38 IS - 3 SP - 032801 PB - AIP Publishing ER - TY - JOUR A1 - Kleshch, Victor I. A1 - Serbun, Pavel A1 - Lützenkirchen-Hecht, Dirk A1 - Orekhov, Anton A1 - Ivanov, Victor E. A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Obraztsov, Alexander N. T1 - A Comparative Study of Field Emission from Pristine, Ion-treated and Tungsten Nanoparticle-decorated p-type Silicon Tips JF - Physica Status Solidi B N2 - The field electron emission characteristics of individual tips of a silicon field emitter array are analyzed. The array of conical‐shaped tips is fabricated on a p‐type silicon wafer by using reactive ion etching and sharpening oxidation. The tips are decorated with single tungsten nanoparticles at their apexes. Furthermore, the focused ion beam is also used to increase surface conductivity of some of the tips. Comparative measurements of field emission are performed by using the scanning anode probe field emission microscopy technique. All types of tips demonstrated emission activation consisting of a sudden current increase at a certain value of the applied voltage. Compared to the pristine tips, a noticeable reduction of the saturation effect in the current–voltage characteristics and a smaller light sensitivity for the decorated tips is found. For ion‐treated tips, saturation effects and light sensitivity are completely suppressed. Scanning electron microscopy observations reveal the formation of single nanoscale protrusions extending from the metal particles and from the apexes of bare ion‐treated tips after exposure under strong electric fields during the field emission measurements. The influence of protrusions growth on characteristics of silicon field emitter arrays is discussed. Y1 - 2019 U6 - https://doi.org/10.1002/pssb.201800646 VL - 256 IS - 9 PB - Wiley ER - TY - CHAP A1 - Serbun, Pavel A1 - Porshyn, Vitali A1 - Müller, Günter A1 - Lützenkirchen-Hecht, Dirk A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Field emission behavior of single n- and p-type black Si pillar structures T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - We have investigated the properties of single n- and p-type black silicon (b-Si) pillars with a height of 20 μ m under strong electric field and halogen lamp or laser illumination. For both type of b-Si pillar structures, I-V measurements revealed strong activation effects, which consisted in sudden current increases during the first up/down voltage sweeps. The maximum reproducible emission current from a single n-type b-Si pillar structure was about 15 μ A. A pronounced saturation region at 240 nA was observed for a single p-type b-Si pillar. The current fluctuation over time showed a standard deviation of 28% and 2.5% for n- and p-type single b-Si pillar structures, respectively. Optical switching under halogen lamp illumination resulted in at least 3 times higher saturation currents and showed a linear dependence of the FE current on the laser power. KW - field emission KW - black silicon KW - photoemission Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520292 PB - IEEE ER - TY - JOUR A1 - Mingels, Stephan A1 - Porshyn, Vitali A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Lützenkirchen-Hecht, Dirk A1 - Müller, Günter T1 - Photosensitivity of p-type black Si field emitter arrays JF - Journal of Applied Physics N2 - We have investigated the properties of black Si field emitter arrays under strong electric fields and laser illumination. A low onset field of 1.8 MV/m for an emission current of 1 nA was obtained. A pronounced saturation region of the dark and photo-enhanced current was observed, which provided a short-term stability of 0.1% at 0.4 μA and 0.7% at 1.0 μA, respectively. As maximum value for the photosensitivity, an on-off current switching ratio of 43 reaching about 13 μA was achieved at a laser power of 15 mW. Electron spectra in the dark and under laser illumination are presented, showing a current and light-sensitive voltage drop across the emitters as well as hints for hot electron emission. Y1 - 2016 U6 - https://doi.org/10.1063/1.4948328 VL - 119 IS - 16 ER - TY - CHAP A1 - Serbun, Pavel A1 - Porshyn, Vitali A1 - Müller, Günter A1 - Mingels, Stephan A1 - Lützenkirchen-Hecht, Dirk A1 - Bachmann, Michael A1 - Düsberg, Felix A1 - Dams, Florian A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Field emission behavior of Au-tip-coated p-type Si pillar structures T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - Precisely aligned high-aspect-ratio (HAR) silicon tip arrays were fabricated using enhanced reactive ion etching with an inductively-coupled-plasma followed by a sharpening oxidation. A gold thin film was then sputtered only on the tips of the HAR structures. Field-emission (FE) properties from Au-coated HAR p-Si tip array cathodes have been systematically investigated by means of field emission scanning microscopy (FESM). A rather high efficiency of the HAR Si structures (71% at 550 V), but limited homogeneous FE with currents of 1-600 nA might be correlated with the varying geometry of the tips and the presence of oxides. I-V measurements of single Au-coated HAR emitters revealed activation effects and the saturation current region at 3 nA. An increase of the saturation current by 4 orders of magnitude was observed during 20 hours of conditioning at constant voltage, which finally resulted in nearly reproducible FN curves with a ß-factor of 473. An excellent stability of the emission current of less than 1 % was obtained during the additional long-time conditioning at constant voltage. Optical switching under halogen lamp illumination resulted in at least 2 times higher saturation currents and showed a linear dependence of the FE current on the light color temperature. KW - field emission KW - p-type Si-pillar array KW - surface oxide effects KW - photoemission Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551516 SN - 2380-6311 SP - 181 EP - 182 PB - IEEE ER - TY - CHAP A1 - Serbun, Pavel A1 - Porshyn, Vitali A1 - Lützenkirchen-Hecht, Dirk A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Photosensitivity of single silicon high-aspect-ratio tips with different doping levels T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - Photosensitivity of single lightly p-doped, highly p-doped, with an integrated p/n junction and intrinsic high-aspect-ratio (HAR) silicon tips was investigated in an ultra-high vacuum environment. The current-voltage characteristics (I-V) of the lightly doped p-type HAR tips showed a characteristic current saturation at around 10-12 nA, whereas the HAR Si tips with p/n junction showed similar saturation phenomena, however, at much smaller current values starting at ~20-30 pA. Optical switching under a halogen lamp illumination resulted in at least 2-4 times higher saturation currents and showed a linear dependence between the illumination power and the FE current, for both types of structures. In case of the highly p-doped HAR tips optical current switching effects, i. e. current saturation, were observed at rather low current levels 1-2 pA. Intrinsic HAR Si-tips showed relative unstable field emission behavior without a clear evidence of the photosensitivity. KW - field emission KW - Si p/n junction KW - p-type Si KW - photosensitivity Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520288 PB - IEEE ER - TY - CHAP A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Dams, Florian A1 - Bachmann, Michael A1 - Düsberg, F. A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Serbun, Pavel A1 - Mingels, Stephan A1 - Müller, Günter T1 - Semiconductor field emission electron sources using a modular system concept for application in sensors and x-ray-sources T2 - 2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China N2 - Semiconductor field emitters are suitable candidates for applications, which require a very stable field emission (FE) current and a high emission uniformity over the entire emission area. By using different materials and geometries, we are able to vary the FE characteristics within a wide range. Each specific application requires its own optimized design for the cathode as well as for the other parts of the FE electron source. To meet as many of these requirements as possible while using only a limited number of different prefabricated components, we established a modular system concept for our FE electron source. This allows the implementation of almost every cathode material. For first characterizations, we used gated p-type Si cathodes with 16 tips. We obtained stable FE currents of 0.4 μA for a grid-potential of 400 V and a gate potential of 100 V. Almost 100% of the electrons are emitted towards the grid-electrode. Parasitic leakage paths, as well as the electron emission towards the gate-electrode can be neglected. Approximately 10% of the electrons are transmitted through the grid and reach the external anode. This is in good agreement with the optical transmission through the grid-mesh. KW - Anodes KW - CATHODES KW - electron sources KW - GEOMETRY KW - Iron KW - Logic gates KW - semiconductor field emission KW - silicon Y1 - 2015 U6 - https://doi.org/10.1109/IVNC.2015.7225572 SP - 178 EP - 179 PB - IEEE ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Schreiner, Rupert A1 - Mingels, Stephan A1 - Porshyn, Vitali A1 - Serbun, Pavel A1 - Müller, Günter T1 - Field emission from surface textured GaN with buried double-heterostructures T2 - 2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China N2 - In this contribution we report on field emission (FE) cathodes based on thin-film LED-technology and surface texturing. The FE cathode can be used both as an n-GaN cathode with an electrical contact at the top side metallization as well as a pn-GaN diode contacting only the p-GaN layer at the bottom side of the structure. The local and integral FE properties of the textured surface of the LED structure were investigated. For n-GaN an integral emission current up to 1.0 μA at an electric field of 19 V/μm was achieved. The pn-GaN diode measurements showed an integral current saturation behavior with two orders of magnitude lower FE currents. Regulated voltage scans obtained by FE scanning microscopy revealed a well-distributed emission over the whole cathode area. Measurements under pulsed tunable laser illumination and moderate electric fields indicated charge carrier generation in the buried double-heterostructures at photon energies below 3.5 eV besides normal photoemission above 4.1 eV. KW - CATHODES KW - Current measurement KW - Electric fields KW - field emission KW - Gallium nitride KW - GaN KW - Iron KW - Light emitting diodes KW - photoemission KW - Surface texture Y1 - 2015 U6 - https://doi.org/10.1109/IVNC.2015.7225548 SP - 106 EP - 107 PB - IEEE ER - TY - CHAP A1 - Mingels, Stephan A1 - Porshyn, Vitali A1 - Serbun, Pavel A1 - Lützenkirchen-Hecht, Dirk A1 - Müller, Günter A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Lutzenkirchen-Hecht, Dirk T1 - Photo-enhanced field emission properties of p-doped black Si arrays T2 - 2016 29th International Vacuum Nanoelectronics Conference (IVNC), 11-15 July 2016, Vancouver, BC, Canada N2 - We have carried out systematic investigations of p-type black Si field emitter arrays under laser illumination. As expected the current-voltage characteristic revealed a strong saturation providing a high photosensitivity, which had a maximum on-off ratio of 43 at a maximum current of 13 μA. The saturation current was stable in the dark as well as under illumination with fluctuations <;0.7%. Results from time-resolved measurements of the photo-sensitivity showed a rather fast response but a long decay time. Electron spectra in the dark and under laser illumination revealed the origin of the emission. KW - black Si KW - Decision support systems KW - photo-enhanced field emission Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551447 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Mingels, Stephan A1 - Serbun, Pavel A1 - Müller, Günter T1 - Field emission from surface textured extraction facets of GaN light emitting diodes T2 - 26th International Vacuum Nanoelectronics Conference (IVNC), 8-12 July 2013, Roanoke, VA, USA N2 - We report on the field emission properties of GaN LED surfaces. The textured extraction facet acts both as light scattering layer in order to increase the light extraction efficiency of the LED as well as nanostructured cathode surface for the field emission (FE) of electrons. The LED emits blue light with a peak wavelength of around 450 nm. The FE properties were investigated by a scanning microscope. Integral measurements as well as regulated voltage scans for 1 nA FE current over an area of 400 * 400 µm2were used to investigate both overall and local FE properties. A high number of well-distributed emitters with an average field enhancement factor ß of 85 and stable integral emission currents up to 100 µA at an electric field of   80 V/µm (Øanode= 880 µm) were found. Photo-field-emission spectroscopy (PFES) using a tunable pulsed laser revealed an enhanced photo absorption of the InGaN/GaN quantum well structures near the emission wavelength of the LED (<3.5 eV), whereas at high photon energies (>4.1 eV) photoemission from the GaN surface was observed. KW - Gallium nitride KW - Iron KW - Light emitting diodes KW - Cathodes KW - Surface texture KW - Surface waves KW - Photonics Y1 - 2013 U6 - https://doi.org/10.1109/ivnc.2013.6624721 PB - IEEE ER - TY - CHAP A1 - Navitski, Aliaksandr A1 - Serbun, Pavel A1 - Müller, Günter A1 - Schreiner, Rupert A1 - Dams, Florian T1 - Efficient and reliable field emission from silicon tip arrays for miniaturized electron sources T2 - 2011 24th International Vacuum Nanoelectronics Conference ; 18-22 July 2011 Wuppertal N2 - Silicon-based cathodes with precisely aligned field emitter arrays (FEA) applicable for miniaturized electron sources were successfully developed and fabricated. The cathode chips contain about 3×105 Si tips/cm2 in a triangular array with a tip height of 2.5 μm, tip radius of 20 nm, and lateral distance between tips of 20 μm. Amazingly homogeneous and well-aligned field emission (FE) from all tips (i.e. 100% efficiency) and maximum stable currents of typically 0.1 μA for p- and 0.6 μA for n-type Si were reproducibly achieved. Current-voltage characteristics of p-type Si tips exhibit the expected saturation at around 10 nA due to limited supply of electrons from a depletion layer, while the n-type Si tips show the usual FN behaviour. Additional coating of the Si tips with a 10 nm Au layer resulted in at least 5 times higher average FE current levels i.e. typically 3 μA but lead, however, to a 30% increase of the onset voltage. KW - cathodes KW - coatings KW - elemental semiconductors KW - field emission KW - field emitter arrays KW - miniaturized electron sources KW - silicon tips KW - structured cold cathode Y1 - 2011 UR - https://ieeexplore.ieee.org/document/6004567?arnumber=6004567 SN - 978-3-00-035081-8 SN - 978-1-4577-1243-2 SN - 2380-6311 SN - 2164-2370 SP - 71 EP - 72 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Pirker, Luka A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert A1 - Remškar, Maja A1 - Višić, Bojana T1 - MoₓWₓ₋₁S₂ Nanotubes for Advanced Field Emission Application JF - Advanced Functional Materials N2 - Transition metal dichalcogenide (TMDC) nanotubes complement the field of low-dimensional materials with their quasi-1D morphology and a wide set of intriguing properties. By introducing different transition metals into the crystal structure, their properties can be tailored for specific purpose and applications. Herein, the characterization and a subsequent preparation of single-nanotube field emission devices of MoxWx-1S2 nanotubes prepared via the chemical vapor transport reaction is presented. Energy-dispersive X-ray spectroscopy, Raman spectroscopy, and X-ray diffraction indicate that the molybdenum and tungsten atoms are randomly distributed within the crystal structure and that the material is highly crystalline. High resolution transmission electron microscopy and electron diffraction (ED) patterns further corroborate these findings. A detailed analysis of the ED patterns from an eight-layer nanotube reveal that the nanotubes grow in the 2H structure, with each shell consists of one bilayer. The work function of the nanotubes is comparable to that of pure MoS2 and lower of pure WS2 NTs, making them ideal candidates for field emission applications. Two devices with different geometrical setup are prepared and tested as field emitters, showing promising results for single nanotube field emission applications. Y1 - 2023 U6 - https://doi.org/10.1002/adfm.202213869 SN - 1616-3028 N1 - Early View. Online Version of Record before inclusion in an issue SP - 1 EP - 8 PB - Wiley ER - TY - JOUR A1 - Broser, Christian A1 - Falter, Thomas A1 - Ławrowski, Robert Damian A1 - Altenbuchner, Amelie A1 - Vögele, Daniel A1 - Koss, Claus A1 - Schlamp, Matthias A1 - Dunnweber, Jan A1 - Steffens, Oliver A1 - Heckner, Markus A1 - Jaritz, Sabine A1 - Schiegl, Thomas A1 - Corsten, Sabine A1 - Lauer, Norina A1 - Guertler, Katherine A1 - Koenig, Eric A1 - Haug, Sonja A1 - Huber, Dominik A1 - Birkenmaier, Clemens A1 - Krenkel, Lars A1 - Wagner, Thomas A1 - Justus, Xenia A1 - Saßmannshausen, Sean Patrick A1 - Kleine, Nadine A1 - Weber, Karsten A1 - Braun, Carina N. A1 - Giacoppo, Giuliano A1 - Heinrich, Michael A1 - Just, Tobias A1 - Schreck, Thomas A1 - Schnabl, Andreas A1 - Gilmore, Amador Téran A1 - Roeslin, Samuel A1 - Schmid, Sandra A1 - Wellnitz, Felix A1 - Malz, Sebastian A1 - Maurial, Andreas A1 - Hauser, Florian A1 - Mottok, Jürgen A1 - Klettke, Meike A1 - Scherzinger, Stefanie A1 - Störl, Uta A1 - Heckner, Markus A1 - Bazo, Alexander A1 - Wolff, Christian A1 - Kopper, Andreas A1 - Westner, Markus A1 - Pongratz, Christian A1 - Ehrlich, Ingo A1 - Briem, Ulrich A1 - Hederer, Sebastian A1 - Wagner, Marcus A1 - Schillinger, Moritz A1 - Görlach, Julien A1 - Hierl, Stefan A1 - Siegl, Marco A1 - Langer, Christoph A1 - Hausladen, Matthias A1 - Schreiner, Rupert A1 - Haslbeck, Matthias A1 - Kreuzer, Reinhard A1 - Brückl, Oliver A1 - Dawoud, Belal A1 - Rabl, Hans-Peter A1 - Gamisch, Bernd A1 - Schmidt, Ottfried A1 - Heberl, Michael A1 - Gänsbauer, Bianca A1 - Bick, Werner A1 - Ellermeier, Andreas A1 - Monkman, Gareth J. A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Tschurtschenthaler, Karl A1 - Aurbach, Maximilian A1 - Dendorfer, Sebastian A1 - Betz, Michael A. A1 - Szecsey, Tamara A1 - Mauerer, Wolfgang A1 - Murr, Florian ED - Baier, Wolfgang T1 - Forschung 2018 T3 - Forschungsberichte der OTH Regensburg - 2018 KW - Forschung KW - Forschungsbericht Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-13826 SN - 978-3-9818209-5-9 CY - Regensburg ER - TY - JOUR A1 - Rück, Thomas A1 - Bierl, Rudolf A1 - Lechner, Alfred A1 - Graf, Antonia A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Auchter, Eberhard A1 - Kriz, Willy A1 - Deubzer, MIchael A1 - Schiller, Frank A1 - Mottok, Jürgen A1 - Niemetz, Michael A1 - Margull, Ulrich A1 - Hagel, Georg A1 - Utesch, Matthias A1 - Waldherr, Franz A1 - Böhm, Matthias A1 - Fraunhoffer, Judith A1 - Gardeia, Armin A1 - Schneider, Ralph A1 - Streubel, Janet A1 - Landes, Dieter A1 - Studt, Reimer A1 - Peuker, Dominik A1 - Scharfenberg, Georg A1 - Hook, Christian A1 - Schuster, Dietwald A1 - Ehrlich, Ingo A1 - Dinnebier, Heinrich A1 - Briem, Ulrich A1 - Lämmlein, Stephan A1 - Koder, Alexander A1 - Bialek, Adam A1 - Genewsky, Axel A1 - Neumeier, Michael A1 - Schlosser, Philipp A1 - Rabl, Hans-Peter A1 - Paule, Matthias A1 - Galster, Christoph A1 - Schiedermeier, Michael A1 - Zwickel, Andreas A1 - Hobmeier, Christoph A1 - Bischoff, Tobias A1 - Rill, Georg A1 - Schaeffer, Thomas A1 - Arbesmeier, Martin A1 - Groß, Andreas A1 - Schlegl, Thomas A1 - Becker, Mark A1 - Senn, Konrad A1 - Schliekmann, Claus A1 - Scholz, Peter A1 - Sippl, Christian A1 - Grill, Martin ED - Eckstein, Josef T1 - Forschungsbericht 2011 / Hochschule für Angewandte Wissenschaften - Fachhochschule Regensburg T3 - Forschungsberichte der OTH Regensburg - 2011 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-7321 SN - 1868-3533 CY - Regensburg ER - TY - CHAP A1 - Herdl, Florian A1 - Bachmann, Michael A1 - Wohlfartsstätter, Dominik A1 - Düsberg, Felix A1 - Dudeck, Markus A1 - Eder, Magdalena A1 - Meyer, Manuel A1 - Pahlke, Andreas A1 - Edler, Simon A1 - Schels, Andreas A1 - Hansch, Walter A1 - Schreiner, Rupert A1 - Wohlfartsstatter, Dominik A1 - Dusberg, Felix T1 - A novel current dependent field emission performance test T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France N2 - A current dependent performance test for comparison of different field emitter arrays is introduced. Statistical analysis is enabled due to a short measurement time and as a main feature the electric field shift, comparable to the degradation of the emitter is examined. Significance of the test method is shown by a comparison of field emitter arrays with different doping levels. KW - Current measurement KW - Field emitter arrays KW - Statistical analysis KW - Systematics KW - Time measurement KW - Tools KW - Vacuum systems Y1 - 2021 U6 - https://doi.org/10.1109/IVNC52431.2021.9600695 SP - 1 EP - 2 ER - TY - CHAP A1 - Bieker, Johannes A1 - Roustaie, Farough A1 - Schlaak, Helmut F. A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Field emission characterization of in-situ deposited metallic nanocones T2 - 2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany N2 - An in-situ fabrication technique based on ion track etched template electrodeposition of metallic nanocones was used for the production of field emitter cathodes. Gold nanocones with a height of 24 microns, a base diameter between 3 to 4 microns and a tip diameter below 300 nanometers were deposited on a circular electrode with a diameter of 2.5 mm. The integral field emission (FE) measurements of samples with cone densities of 6 · 104 cones/cm2 (sample A) and 1 · 106 cones/cm2 (sample B) yielded in a maximum current of 37.5 μA at an applied field of 12.5 V/μm for sample A and 29.1 μA at 9.4 V/μm for sample B. The stability of emission current was investigated for over 48 hours and no degradation was observed. KW - CATHODES KW - Current measurement KW - FABRICATION KW - field emission KW - ion track template KW - Ions KW - Iron KW - nanocones KW - Vacuum technology KW - Voltage measurement Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051571 SP - 120 EP - 121 PB - IEEE ER - TY - CHAP A1 - Schels, Andreas A1 - Edler, Simon A1 - Hansch, Walter A1 - Bachmann, Michael A1 - Herdl, Florian A1 - Dusberg, F. A1 - Eder, Magdalena A1 - Meyer, Manuel A1 - Dudek, M. A1 - Pahlke, Andreas A1 - Schreiner, Rupert ED - Purcell, Stephen ED - Mazellier, Jean-Paul T1 - Current dependent performance test used on different types of silicon field emitter arrays T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France N2 - A current dependent performance test is used to investigate the influence of doping and emitter geometry on the lifetime of silicon field emitter arrays. The measurements reveal an improved performance for lower n-type dopant concentrations. Furthermore, two new types of field emitters are introduced by slightly varying the original fabrication process [1]. The comparison shows superiority of tip like emitters over blade like structures. Y1 - 2021 SN - 978-1-6654-2589-6 U6 - https://doi.org/10.1109/IVNC52431.2021.9600787 SP - 1 EP - 2 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Schels, Andreas A1 - Herdl, Florian A1 - Hausladen, Matthias A1 - Wohlfartsstätter, Dominik A1 - Edler, Simon A1 - Bachmann, Michael A1 - Pahlke, Andreas A1 - Schreiner, Rupert A1 - Hansch, Walter T1 - Quantitative Field Emission Imaging for Studying the Doping-Dependent Emission Behavior of Silicon Field Emitter Arrays JF - Micromachines N2 - Field emitter arrays (FEAs) are a promising component for novel vacuum micro- and nanoelectronic devices, such as microwave power amplifiers or fast-switching X-ray sources. However, the interrelated mechanisms responsible for FEA degradation and failure are not fully understood. Therefore, we present a measurement method for quantitative observation of individual emission sites during integral operation using a low-cost, commercially available CMOS imaging sensor. The emission and degradation behavior of three differently doped FEAs is investigated in current-regulated operation. The measurements reveal that the limited current of the p-doped emitters leads to an activation of up to 55% of the individual tips in the array, while the activation of the n-type FEA stopped at around 30%. This enhanced activation results in a more continuous and uniform current distribution for the p-type FEA. An analysis of the individual emitter characteristics before and after a constant current measurement provides novel perspectives on degradation behavior. A burn-in process that trims the emitting tips to an integral current-specific ideal field enhancement factor is observed. In this process, blunt tips are sharpened while sharp tips are dulled, resulting in homogenization within the FEA. The methodology is described in detail, making it easily adaptable for other groups to apply in the further development of promising FEAs. Y1 - 2023 U6 - https://doi.org/10.3390/mi14112008 VL - 14 IS - 11 PB - MDPI ER - TY - CHAP A1 - Schels, Andreas A1 - Herdl, Florian A1 - Hausladen, Matthias A1 - Wohlfartsstätter, Dominik A1 - Bachmann, Michael A1 - Edler, Simon A1 - Düsberg, Felix A1 - Pahlke, Andreas A1 - Buchner, Philipp A1 - Schreiner, Rupert A1 - Hansch, Walter T1 - Beta Factor Mapping of Individual Emitting Tips During Integral Operation of Field Emission Arrays T2 - 2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA N2 - Emission uniformity mappings of field emitter arrays provide important insight into degradation mechanisms, but are often laborious, non-integral, costly, or not quantifiable. Here, a low-cost Raspberry Pi HQ camera is used as an extraction anode to quantify the emission distribution in field emitter arrays. A verification measurement using controlled SEM electron beams proves, that current-voltage characteristics of individual emission sites can be determined by combining the integral electrical data with the image data. The characteristics are used to quantify the field enhancement factors of an 30x30 silicon field emitter array during integral operation. Comparison of the field enhancement factor distributions before and after a one-hour constant current operation at 1 µA shows an increase from 50 actively emitting tips before to 156 after the measurement. It is shown, that the distribution of field enhancement factors shifts towards lower values, due to the increasing degradation for high field enhancement tips, especially above 1500. KW - field emission KW - field emission imaging KW - field emission distribution KW - field enhancement factor KW - CMOS imaging KW - beta factor Y1 - 2023 SN - 979-8-3503-0143-4 U6 - https://doi.org/10.1109/IVNC57695.2023.10188957 SP - 224 EP - 226 PB - IEEE ER - TY - CHAP A1 - Herdl, Florian A1 - Kueddelsmann, Maximillian J. A1 - Schels, Andreas A1 - Bachmann, Michael A1 - Edler, Simon A1 - Wohlfartsstätter, Dominik A1 - Düsberg, Felix A1 - Prugger, Alexander A1 - Dillig, Michael A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Coileáin, Cormac Ó. A1 - Zimmermann, Stefan A1 - Pahlke, Andreas A1 - Duesberg, Georg S. T1 - Characterization and Operation of Graphene-Oxide-Semiconductor Emitters at Atmospheric Pressure Levels T2 - 2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA N2 - In recent years Graphene-Oxide-Semiconductor (GOS) electron emitters have attracted a lot of interest due to their outstanding durability in modest vacuum conditions. However, the performance at ambient pressure remains largely unexplored. In this study GOS-emitters are characterized in nitrogen and air at atmospheric pressure, and compared with their vacuum characteristics. For this purpose, lifetime and IV-characteristics measurements are shown. Furthermore, the GOS-emitter was operated as an ionization source for ion mobility spectrometry (IMS) at ambient conditions. KW - durability KW - graphene compounds KW - ion mobility KW - semiconductor-insulator boundaries Y1 - 2023 SN - 979-8-3503-0143-4 U6 - https://doi.org/10.1109/IVNC57695.2023.10188974 SP - 14 EP - 16 PB - IEEE ER - TY - CHAP A1 - Hausladen, Matthias A1 - Buchner, Philipp A1 - Schels, Andreas A1 - Edler, Simon A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - An Integrated Field Emission Electron Source on a Chip Fabricated by Laser-Micromachining and Mems Technology T2 - 2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA N2 - A silicon field emission electron source consisting of a cathode and a grid electrode has been fabricated by laser micromachining. The cathode features 21×21 tips on an area of 4×4 mm 2 , With a self-aligning MEMS technology for the aperture grid, a high electron transmission (99 %) was achieved. Onset voltages of 50…70 V were observed for an emission current of 1 nA. A stable emission current of 1 mA ± 1.3 % at an extraction voltage of 250 V was observed during a 30-min operation. KW - Apertures KW - Field Emission KW - Field Emission Array KW - Ions KW - Laser-Micromachining KW - Lasers KW - Micromechanical devices KW - Silicon KW - Silicon Field Emission Array KW - Steady-state KW - Vacuum systems Y1 - 2023 SN - 979-8-3503-0143-4 U6 - https://doi.org/10.1109/IVNC57695.2023.10189001 SP - 115 EP - 116 PB - IEEE ER - TY - CHAP A1 - Buchner, Philipp A1 - Hausladen, Matthias A1 - Schels, Andreas A1 - Herdl, Florian A1 - Edler, Simon A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - An Integrated Silicon Nanowire Field Emission Electron Source on a Chip with High Electron Transmission T2 - 2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA N2 - Silicon nanowire field emission arrays (50 × 50 pillars) were fabricated on a silicon glass hybrid wafer. The glass acts both as the support for the whole structure and insulator between cathode and extraction grid. The extraction grid matches the emitter structures and is optically aligned and adhered to the emitter chip by a vacuum compatible epoxide adhesive. These chips exhibit an emission current of about 600 μA at an extraction voltage of 300 V. The electron transmission through the grid is above 80 %. 58-hour longtime measurements were conducted showing low degradation of the emission current and high stability of electron transmission. KW - Semiconductor device measurement KW - Stimulated emission KW - Optical device fabrication KW - Glass KW - Power system stability KW - Insulators KW - Electron optics Y1 - 2023 SN - 979-8-3503-0143-4 U6 - https://doi.org/10.1109/IVNC57695.2023.10188878 SP - 6 EP - 8 PB - IEEE ER - TY - CHAP A1 - Hausladen, Matthias A1 - Schels, Andreas A1 - Buchner, Philipp A1 - Bartl, Mathias A1 - Asgharzade, Ali A1 - Edler, Simon A1 - Wohlfartsstätter, Dominik A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Improved Method for Determining the Distribution of FEA Currents by Optical CMOS Sensors T2 - 37th International Vacuum Nanoelectronics Conference (IVNC), 15-19 July 2024, Brno, Czech Republic N2 - CMOS image sensors are utilized to determine the time- and spatially-resolved distribution of the electron emission of silicon field emission arrays. During initial experiments, rather low field emission currents already visibly damaged the sensor surface, altering the system accuracy over the measurement time. Therefore, we coated the sensor surface with copper for protection. In contrast to the original insulating surface, the Cu coating provides a conductive surface for incident electrons and improves heat dissipation in addition. This prevents localized surface charges and surface damages which stabilize the system accuracy. Y1 - 2024 U6 - https://doi.org/10.1109/IVNC63480.2024.10652543 SP - 1 EP - 2 PB - IEEE ER - TY - JOUR A1 - Bachmann, Michael A1 - Düsberg, Felix A1 - Pahlke, Andreas A1 - Edler, Simon A1 - Schels, Andreas A1 - Herdl, Florian A1 - Hausladen, Matthias A1 - Buchner, Philipp A1 - Schreiner, Rupert T1 - The “LED‐version” of the electron gun: An electron source for operation in ambient pressure environments based on silicon field emitter arrays JF - Vakuum in Forschung und Praxis N2 - We report on our progress to develop and optimize electron sources for practical applications. A simple fabrication process is introduced based on a wafer dicing saw and a wet chemical etch step without the need for a clean room. Due to the formation of crystal facets the samples show a homogeneous geometry throughout the array. Characterization techniques are developed to systematically compare various arrays. A very defined measurement procedure based on current controlled IV-sweeps as well as lifetime measurements at various currents is proposed. To investigate the current distribution in the array a commercial CMOS detector is used and shows the potential for in depth analysis of the arrays. Finally, a compact hermetically sealed housing is presented enabling electron generation in atmospheric pressure environments. Y1 - 2023 U6 - https://doi.org/10.1002/vipr.202300801 VL - 35 IS - 3 SP - 32 EP - 37 PB - Wiley ER - TY - JOUR A1 - Hausladen, Matthias A1 - Schels, Andreas A1 - Buchner, Philipp A1 - Bartl, Mathias A1 - Asgharzade, Ali A1 - Edler, Simon A1 - Wohlfartsstätter, Dominik A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Measurement of field emission array current distributions by metal-coated CMOS image sensors JF - Journal of Vacuum Science & Technology B N2 - A CMOS image sensor is utilized to determine the time- and spatially resolved distribution of the total electron emission current of a silicon field emission array. The sensor measures electron emission without the need for phosphorus screens or scintillators as converters. However, in initial experiments, rather low field emission currents of several hundreds of nanoamperes per emitter already damaged the sensor surface, which altered the systems’ signal response over the measurement time. In consequence, we coated the CMOS sensor surface with a Cu layer for surface protection. In contrast to the original insulating surface, Cu is an excellent current- and heat-conductor, which avoids lens charging by providing a conductive path for incident electrons and has an improved heat dissipation capability. Measurements using a segmented field emission cathode with four individually addressable tips demonstrate a consistent correlation between the emission current and the sensor signal of the metal-coated image sensor. Furthermore, the characterization of a field emission array showed that single tip emission currents of up to 12 μA per tip are measurable without discernible damage effects of the sensor’s surface. KW - Bremsstrahlung KW - Laser micromachining KW - Image sensors KW - Field emitter arrays Y1 - 2024 U6 - https://doi.org/10.1116/6.0004074 VL - 42 IS - 6 PB - AIP Publishing ER - TY - JOUR A1 - Schreiner, Rupert A1 - Wiedmann, J. A1 - Coenning, W. A1 - Porsche, J. A1 - Gentner, Jean-Louis A1 - Berroth, Manfred A1 - Scholz, Ferdinand A1 - Schweizer, H. T1 - Fabrication approach for antiphase narrow linewidth complex coupled 1.55 μm DFB lasers JF - Electronics Letters N2 - A new method for fabricating narrow linewidth antiphase complex coupled MQW DFB lasers by periodically etching the active layer and quartemary InGaAsP overgrowth is reported. The minimum linewidth for a 375 µm long ridge waveguide laser is only 250 kHz at an optical output power of 4 mW. KW - etching KW - optical fabrication KW - quantum well lasers KW - ridge waveguides KW - distributed feedback lasers Y1 - 1999 U6 - https://doi.org/10.1049/el:19990132 SN - 0013-5194 VL - 35 IS - 2 SP - 146 EP - 148 PB - The Institution of Engineering and Technology IET ER - TY - JOUR A1 - Hausladen, Matthias A1 - Schels, Andreas A1 - Asgharzade, Ali A1 - Buchner, Philipp A1 - Bartl, Mathias A1 - Wohlfartsstätter, Dominik A1 - Edler, Simon A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Investigation of Influencing Factors on the Measurement Signal of a CMOS Image Sensor for Measuring Field Emission Currents JF - Sensors Y1 - 2025 U6 - https://doi.org/10.3390/s25051529 N1 - Corresponding author der OTH Regensburg: Matthias Hausladen VL - 25 IS - 5 PB - MDPI ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Sellmair, Josef T1 - Nano Emitters on Silicon Pillar Structures generated by a Focused Electron Beam Induced Deposition T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - Nano emitters were deposited by focused electron beam induced deposition of Trimethyl-(methylcyclopentadienyl)platinum(IV) on top of silicon pillars. The nano emitters were exactly positioned in the center on the top of up to four pillars of a quadratic arranged array of sixteen pillars with a pitch of 50 μm. Integral field emission measurements were performed in a diode configuration with a 50 μm mica spacer in a vacuum chamber at pressures of about 10 -9 mbar. The Fowler-Nordheim plots show a linear behavior, like expected for an n-type silicon material and a metal needle. The I-V measurement of the most promising sample shows an integral emission current up to 2 μm at a voltage of 600 V (12 MV/m) and an onset voltage for a current of 1 nA of about 300 V. KW - field emission KW - nano emitter KW - focused electron beam induced deposition KW - MeCpPtMe3 Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520059 PB - IEEE ER - TY - CHAP A1 - Buchner, Philipp A1 - Hausladen, Matthias A1 - Bartl, Mathias A1 - Schreiner, Rupert T1 - Elektronenquellen basierend auf Feldemission aus Silizium T2 - Tagungsband zum 4. Symposium Elektronik und Systemintegration ESI: 17. April 2024, Hochschule Landshut N2 - Der Beitrag gibt einen Überblick über zwei typische Bauformen für Elektronenquellen auf der Basis von Feldemission aus Silizium. Des Weiteren wird eine typische Trioden-Beschaltung solcher Elektronenquellen für hohe Elektronentransmission vorgestellt und dabei auf ihre Leistungsfähigkeit eingegangen. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-4212 SN - 978-3-9818439-9-6 SP - 46 EP - 53 PB - Hochschule für Angewandte Wissenschaften Landshut CY - Landshut ER - TY - JOUR A1 - Eiler, Julian A1 - Weber, Stefan A1 - Gerlesberger, Peter A1 - Plöchinger, Heinz A1 - Schreiner, Rupert T1 - Active heat-loss compensated miniaturized pirani sensor chip JF - IEEE Sensors Letters N2 - Due to the limited measuring range of commercial Pirani sensors in lower pressure regimes, attempts are being made to extend the measuring range of the sensors. Our approach to extend the measuring range toward lower pressures is a micro-electromechanical systems (MEMS) Pirani sensor with active heat compensation on the suspensions. The sensor element has the shape of a microhotplate and consists of a nickel heating meander embedded in two silicon nitride layers. The whole structure is built on a silicon wafer. The sensor element is suspended on all four corners of the substrate. On each of the suspensions, there is an additional heating structure that minimizes the heat flux from the hot sensor element toward the substrate. The sensor is driven at a constant temperature through a self-balancing Wheatstone bridge. A constant voltage is applied to the heating structures on the suspensions. It has been demonstrated that with these additional heaters, the sensitivity of the sensor can be increased in the high-vacuum regime. This enables reliable vacuum measurements down to 10−6 mbar. KW - Temperature measurement KW - Heating systems KW - Temperature sensors KW - Sensitivity KW - Pressure measurement KW - Voltage measurement KW - Heat sinks KW - Semiconductor device measurement KW - Noise measurement KW - Bridge circuits Y1 - 2025 U6 - https://doi.org/10.1109/LSENS.2025.3605747 SN - 2475-1472 VL - 9 IS - 10 PB - Institute of Electrical and Electronics Engineers (IEEE) ER - TY - GEN A1 - Eiler, Julian A1 - Weber, Stefan A1 - Gerlesberger, Peter A1 - Plöchinger, Heinz A1 - Schreiner, Rupert T1 - Miniaturized Pirani vacuum sensor with active heat-loss compensation T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft e.V. (DPG), Regensburg, 16. - 21. März 2025 N2 - Pirani sensors measure the thermal conductivity of the residual gas in a vacuum by creating a thermal gradient between a heated sensor element and a heat sink. The heat flux from the sensor element to the heat sink over the residual gas is a measure of the vacuum and can be determined by the electrical power applied. In addition to the heat flux over the gas, there are further energy losses from the heating structure due to radiation and parasitic heat fluxes via the suspensions of the sensor element. These losses reduce the sensitivity of the sensor. For this reason, a Micro-Pirani sensor in the shape of a microhotplate was developed that actively compensates the heat flux via the suspensions. This was achieved by placing additional heating structures on the suspensions, which interrupt the heat flow from the sensor element via the suspensions during operation. This active compensation improves the sensitivity at low pressures, enabling vacuum measurements from atmospheric pressure down to 10e-6 mbar. Y1 - 2025 UR - https://www.dpg-verhandlungen.de/year/2025/conference/regensburg/part/o/session/66/contribution/7 SN - 2751-0522 PB - Deutsche Physikalische Gesellschaft e.V. ER - TY - CHAP A1 - Eiler, Julian A1 - Berndt, Dominik A1 - Schreiner, Rupert T1 - Miniaturisierter Wasserstoffsensor basierend auf der 3-Omega Methode T2 - Tagungsband zum 4. Symposium Elektronik und Systemintegration ESI: 17. April 2024, Hochschule Landshut N2 - Die Arbeit stellt einen thermischen Wasserstoffsensor auf Siliziumbasis vor, der mit der 3-Omega Messmethode betrieben wird. Durch das dynamische Messverfahren, die große Sensoroberfläche bei gleichzeitig geringer thermischer Masse und der Materialkombination wird eine Auflösungsgrenze von 55 ppm Wasserstoff in Stickstoff erreicht. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-4205 SN - 978-3-9818439-9-6 SP - 38 EP - 45 PB - Hochschule für Angewandte Wissenschaften Landshut CY - Landshut ER - TY - GEN A1 - Krysztof, Michal A1 - Baranowski, Kamil A1 - Zychla, Michal A1 - Hausladen, Matthias A1 - Schreiner, Rupert A1 - Knápek, Aleksandr T1 - MP61 - Detection of Electron Beam in Atmospheric Pressure Using CMOS Image Sensor T2 - EUROSENSORS XXXVII ; 07.09.2025 - 10.09.2025 ; Wroclaw ; Poster I N2 - In the article, a new detection system that enables observation of the electron beam signal passing through a gas layer at atmospheric pressure is presented. An experimental setup consisting of an elec-tron gun (electron emitter, extraction, and focus electrodes), silicon nitride membrane, and a CMOS image sensor is described, as well as first image of the electron beam spot after passing through 400 µm of air at atmospheric pressure is presented. Y1 - 2025 U6 - https://doi.org/10.5162/EUROSENSORS2025/MP61 SP - 325 EP - 326 PB - AMA ER - TY - CHAP A1 - Bartl, Mathias A1 - Hausladen, Matthias A1 - Asgharzade, Ali A1 - Buchner, Philipp A1 - Krysztof, Michal A1 - Knápek, Alexandr A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Experimental method for investigation of the emission pattern characteristics of individual field emission tips using a CMOS image sensor T2 - 38th International Vacuum Nanoelectronics Conference (IVNC) N2 - The emission pattern characteristics of individual silicon field emission tips were investigated using a CMOS image sensor. The quality of the image was improved by spatial and temporal averaging, so that individual emission centers could be identified and their temporal changes investigated. By mapping the emission current onto the image, the distribution of the current density on the image sensor could be calculated. KW - CMOS image sensors KW - Silicon KW - Current density KW - Nanoelectronics Y1 - 2025 U6 - https://doi.org/10.1109/IVNC65669.2025.11121040 PB - IEEE ER - TY - CHAP A1 - Baranowski, Kamil A1 - Zychla, Michał A1 - Krysztof, Michał A1 - Żółtowski, Michał A1 - Hausladen, Matthias A1 - Schreiner, Rupert A1 - Knápek, Aleksandr T1 - Experimenal method for studying electron beams in gaseous environments using a CMOS image sensor T2 - 38th International Vacuum Nanoelectronics Conference (IVNC) N2 - Detecting and analyzing electron beams in atmospheric conditions remains a significant challenge due to scattering and absorption of electrons by gas molecules. In this work, a novel approach using a CMOS image sensor for real-time electron beam detection after its transmission through air is presented. The setup enables visualization of beam divergence, emission profiles, and dynamic behavior under atmospheric pressure. Presented results demonstrate the potential of CMOS image sensor for electron beam analysis in gaseous environment. Y1 - 2025 SN - 979-8-3315-3705-0 U6 - https://doi.org/10.1109/IVNC65669.2025.11120851 PB - IEEE ER - TY - CHAP A1 - Allaham, Mohammad M. A1 - Burda, Daniel A1 - Knápek, Alexandr A1 - Krysztof, Michał A1 - Baranowski, Kamil A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Testing the performance of tungsten-graphite cathodes as MEMS Electron microscope electron source T2 - 38th International Vacuum Nanoelectronics Conference (IVNC) N2 - This work presents preliminary results of the performance testing of exfoliated graphene layers deposited on the nanotip of a tungsten field emission cathode. The obtained tungsten-graphite cathodes were then operated in a 3D-printed MEMS electron microscope testing model for later applications. The results were promising, where a maximum emission current of 50.2 μA was obtained with an extraction voltage of 1 kV and anode voltage of 3 kV. Y1 - 2025 U6 - https://doi.org/10.1109/IVNC65669.2025.11121041 PB - IEEE ER - TY - CHAP A1 - Asgharzade, Ali A1 - Bartl, Mathias A1 - Hausladen, Matthias A1 - Chen, Yang A1 - Buchner, Philipp A1 - Edler, Simon A1 - Bachmann, Michael A1 - She, Juncong A1 - Schreiner, Rupert T1 - Investigation on the influence of internal voltage drops on the emission behavior of silicon field emission arrays using CMOS image sensor T2 - 38th International Vacuum Nanoelectronics Conference (IVNC) N2 - In this paper we report on an improved measurement and analysis method for determining the emission current distribution of field emitter arrays with CMOS sensors. It can also be used for field emission arrays where not all surfaces of the emitters are at the same electrical potential (e.g. for p-doped Si tips, where a strong current saturation occurs). To demonstrate the functionality of this method, a n-doped field emission array was measured using a variable external series resistance. Brightness variations in emission spots were analyzed to re-calculate the known series resistances for comparison. The re-calculated value is in good agreement with the actual value of the resistance. This method offers a quantitative approach to assess internal voltage drop effects on field emission using optical readout KW - field emission imaging KW - field emission KW - CMOS sensor Y1 - 2025 U6 - https://doi.org/10.1109/IVNC65669.2025.11120937 PB - IEEE ER - TY - JOUR A1 - Buchner, Philipp A1 - Hausladen, Matthias A1 - Bartl, Mathias A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - High current field emission from Si nanowires on pillar structures JF - Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics N2 - We investigate the influence of the geometry and doping level on the performance of n-type silicon nanowire field emitters on silicon pillar structures. Therefore, multiple cathodes with 50 by 50 pillar arrays (diameter: 5 μm, height: 30 μm, spacing: 50 μm) were fabricated and measured in diode configuration. In the first experiment, we compared two geometry types using the same material. Geometry 1 is black silicon, which is a highly dense surface covering a forest of tightly spaced silicon needles resulting from self-masking during a plasma etching process of single crystal silicon. Geometry 2 are silicon nanowires, which are individual spaced-out nanowires in a crownlike shape resulting from a plasma etching process of single crystal silicon. In the second experiment, we compared two different silicon doping levels [n-type (P), 1–10 and <0.005 Ω cm] for the same geometry. The best performance was achieved with lower doped silicon nanowire samples, emitting 2 mA at an extraction voltage of 1 kV. The geometry/material combination with the best performance was used to assemble an integrated electron source. These electron sources were measured in a triode configuration and reached onset voltages of about 125 V and emission currents of 2.5 mA at extraction voltages of 400 V, while achieving electron transmission rates as high as 85.0%. KW - Doping KW - Electron sources KW - Nanowires KW - Plasma processing KW - Field emitter arrays KW - Triodes KW - Semiconductors Y1 - 2024 U6 - https://doi.org/10.1116/6.0003384 SN - 2166-2754 VL - 42 IS - 2 PB - AIP ER - TY - CHAP A1 - Schreiner, Rupert A1 - Mulot, M. A1 - Gauggel, H. P. A1 - Schweizer, H. A1 - Laue, C. K. A1 - Wallenstein, R. T1 - Dynamic and spectral properties of red DFB lasers T2 - Technical Digest. Summaries of papers presented at the Conference on Lasers and Electro-Optics. Postconference Technical Digest (IEEE Cat. No.01CH37170) ; Baltimore, May 6 - 11, 2001 (Trends in optics and photonics series ; 56) N2 - Summary form only given. Narrow linewidth GaInP/AlGaInP DFB lasers are promising light sources for spectroscopy, for optical data storage systems and for plastic optical fiber WDM applications. However, little is known about the dynamic behavior of red DFB lasers. In this paper, we report on the dynamic and spectral properties of those devices. The lasers were first characterized under cw operation at 25/spl deg/C. Threshold currents are /spl sim/14 mA (475 /spl mu/m length) and /spl sim/18 mA (900 /spl mu/m length). The lasers show stable single mode emission at 680 nm with a SMSR better than -25 dB. The spectral linewidth of the 900 /spl mu/m long devices was measured by using a scanning-Fabry-Perot interferometer. Y1 - 2001 UR - http://ieeexplore.ieee.org/document/947498/ SN - 1-55752-662-1 U6 - https://doi.org/10.1109/CLEO.2001.947498 SP - 81 EP - 82 PB - IEEE ER - TY - JOUR A1 - Tan, Jing Jie A1 - Schreiner, Rupert A1 - Hausladen, Matthias A1 - Asgharzade, Ali A1 - Edler, Simon A1 - Bartsch, Julian A1 - Bachmann, Michael A1 - Schels, Andreas A1 - Kwan, Ban-Hoe A1 - Ng, Danny Wee-Kiat A1 - Hum, Yan-Chai T1 - SiMiC: Context-aware silicon microstructure characterization using attention-based convolutional neural networks for field-emission tip analysis JF - Journal of Vacuum Science & Technology B N2 - Accurate characterization of silicon microstructures is essential for advancing microscale fabrication, quality control, and device performance. Traditional analysis using scanning electron microscopy (SEM) often requires labor-intensive, manual evaluation of feature geometry, limiting throughput and reproducibility. In this study, we propose SiMiC: Context-aware Silicon Microstructure Characterization Using Attention-based Convolutional Neural Networks for Field-Emission Tip Analysis. By leveraging deep learning, our approach efficiently extracts morphological features—such as size, shape, and apex curvature—from SEM images, significantly reducing human intervention while improving measurement consistency. A specialized dataset of silicon-based field-emitter tips was developed, and a customized convolutional neural network architecture incorporating attention mechanisms was trained for multiclass microstructure classification and dimensional prediction. Comparative analysis with classical image processing techniques demonstrates that SiMiC achieves high accuracy while maintaining interpretability. The proposed framework establishes a foundation for data-driven microstructure analysis directly linked to field-emission performance, opening avenues for correlating emitter geometry with emission behavior and guiding the design of optimized cold-cathode and SEM electron sources. The related dataset and algorithm repository that could serve as a baseline in this area can be found at https://research.jingjietan.com/?q=SIMIC. KW - Field emitter arrays KW - Quality assurance KW - Convolutional neural network KW - Deep learning KW - Image processing KW - Machine learning KW - Cold cathodes KW - Scanning electron microscopy KW - Electron sources KW - Chemical elements Y1 - 2025 U6 - https://doi.org/10.1116/6.0005068 VL - 43 IS - 6 PB - AVS ER -