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 -