@inproceedings{PrommesbergerLangerŁawrowskietal., author = {Prommesberger, Christian and Langer, Christoph and Ławrowski, Robert Damian and Dams, Florian and Schreiner, Rupert and Ławrowski, Robert Damian}, title = {Gated p-Si field emitter arrays for sensor applications}, series = {2015 28th International Vacuum Nanoelectronics Conference (IVNC)}, booktitle = {2015 28th International Vacuum Nanoelectronics Conference (IVNC)}, publisher = {IEEE}, doi = {10.1109/IVNC.2015.7225567}, pages = {164 -- 165}, abstract = {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.}, language = {en} } @inproceedings{LangerPrommesbergerŁawrowskietal., author = {Langer, Christoph and Prommesberger, Christian and Ławrowski, Robert Damian and M{\"u}ller, F. and Schreiner, Rupert and Serbun, Pavel and M{\"u}ller, G{\"u}nter}, title = {Enhanced field emission from p-doped black silicon on pillar structures}, series = {2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China}, booktitle = {2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China}, publisher = {IEEE}, doi = {10.1109/IVNC.2015.7225547}, pages = {104 -- 105}, abstract = {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.}, language = {en} } @inproceedings{PrommesbergerŁawrowskiLangeretal., author = {Prommesberger, Christian and Ławrowski, Robert Damian and Langer, Christoph and Dams, Florian and Schreiner, Rupert}, title = {Realisierung von Siliziumspitzenarrays mit integrierter Gate-Elektrode f{\"u}r Anwendungen in der Vakuumsensorik}, series = {4. Landshuter Symposium Mikrosystemtechnik, Mikrosystemtechnik als Schl{\"u}sseltechnologie der Systemintegration, Tagungsband zum Symposium 12./13. M{\"a}rz 2014, Hochschule Landshut}, booktitle = {4. Landshuter Symposium Mikrosystemtechnik, Mikrosystemtechnik als Schl{\"u}sseltechnologie der Systemintegration, Tagungsband zum Symposium 12./13. M{\"a}rz 2014, Hochschule Landshut}, address = {Landshut}, isbn = {978-3-9812696-5-9}, pages = {36 -- 41}, abstract = {Bei der Feldemission (kalte Emission) k{\"o}nnen Elektronen durch ein starkes elektrisches Feld eine glatte und leitende Oberfl{\"a}che verlassen. Die Elektronen tunneln dabei durch eine Potentialbarriere, deren Breite durch ein {\"a}ußeres elektrisches Feld verkleinert wird. Durch das Hinzuf{\"u}gen einer integrierten Gate-Elektrode um eine Siliziumspitze kann die notwendige Einsatzspannung f{\"u}r Feldemission deutlich gesenkt werden. Zwischen Si-Kathode und Gate-Elektrode befindet sich dabei eine Isolationsschicht, die h{\"o}chste Anforderungen bez{\"u}glich der elektrischen Durchbruchsfestigkeit erf{\"u}llen 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 Durchbruchsfeldst{\"a}rke von 3,2 MV/cm aufweist. F{\"u}r die Realisierung von Siliziumkathoden mit integrierter Gate-Elektrode wurde ein bereits bestehender Herstellungsprozess um zus{\"a}tzliche Prozessschritte erweitert. Die {\"U}bertragung der lateralen Position der Spitze erfolgt durch Strukturierung des Umkehrlacks AZ5214 und einer RIE-{\"A}tzung der zuvor hergestellten SiO2-Schicht. Nach dem Entfernen der Lackschicht wird die vertikale Struktur der Siliziumspitzen durch einen RIE-{\"A}tzprozess 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 Ansch{\"a}rfeoxidation auch zur Realisierung der endg{\"u}ltigen Spitzengeometrie verwendet. Durch die lithographische Strukturierung des Photolacks AZ5214 kann dabei die Fl{\"a}che 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 Oxidpl{\"a}ttchen nicht komplett von Metall ummantelt wird. Die Opferschicht aus Photolack wird mit den nicht ben{\"o}tigten Metallfl{\"a}chen in einem Lift-off-Prozess entfernt.}, language = {de} } @inproceedings{ŁawrowskiLangerPrommesbergeretal., author = {Ławrowski, Robert Damian and Langer, Christoph and Prommesberger, Christian and Dams, Florian and Serbun, Pavel and M{\"u}ller, G{\"u}nter and Schreiner, Rupert}, title = {Spitzen- und Kantenemitter aus Silizium mit einem hohen Aspektverh{\"a}ltnis f{\"u}r Ionisationsgassensoren}, series = {Mikrosystemtechnik als Schl{\"u}sseltechnologie der Systemintegration : 4. Landshuter Symposium Mikrosystemtechnik ; Tagungsband zum Symposium ; 12./13. M{\"a}rz 2014, Hochschule Landshut}, booktitle = {Mikrosystemtechnik als Schl{\"u}sseltechnologie der Systemintegration : 4. Landshuter Symposium Mikrosystemtechnik ; Tagungsband zum Symposium ; 12./13. M{\"a}rz 2014, Hochschule Landshut}, publisher = {Cluster Mikrosystemtechnik}, address = {Landshut}, isbn = {978-3-9812696-5-9}, pages = {28 -- 35}, abstract = {Durch die Optimierung von reaktivem Ionen{\"a}tzen mit induktiv gekoppeltem Plasma ist die Herstellung von verschiedenen Siliziumkathoden mit hoher Anisotropie und hohem Aspektverh{\"a}ltnis f{\"u}r Feldemissionsanwendungen m{\"o}glich. Simulationen mit COMSOL Multiphysics untermauern das Potential von solchen Spitzen- und Kantenfeldemittern. Die Ergebnisse der Simulation zeigen einen zwei- bis sechsfach h{\"o}heren Feld{\"u}berh{\"o}hungsfaktor der tiefge{\"a}tzten Strukturen im Vergleich zu identischen Emittern ohne zus{\"a}tzliche Tiefen{\"a}tzung. Feldemissionsmessungen best{\"a}tigen die Simulationsergebnisse. Der modifizierte Herstellungsprozess der Feldemitter erm{\"o}glicht somit einen zuverl{\"a}ssigen Betrieb von Feldemissionselektronenquellen bei kleineren makroskopischen Feldst{\"a}rken. Außerdem weisen die Messungen des Emissionsstroms im S{\"a}ttigungsbereich eine weitgehende Unabh{\"a}ngigkeit vom elektrischen Feld auf. Lokale Feldemissionsmessungen ergeben dadurch eine deutliche Stromstabilisierung, welche {\"u}ber große Feldst{\"a}rkenbereiche konstant bleibt. Die Nutzung der HAR-Emitter (high aspect ratio) ist damit eine gute Voraussetzung f{\"u}r einen zuverl{\"a}ssigen Betrieb der Emissionskathoden bei kleinen Feldst{\"a}rken f{\"u}r die Anwendung in Ionisationsgassensoren.}, language = {de} } @article{ŁawrowskiPrommesbergerLangeretal., author = {Ławrowski, Robert Damian and Prommesberger, Christian and Langer, Christoph and Dams, Florian and Schreiner, Rupert}, title = {Improvement of Homogeneity and Aspect Ratio of Silicon Tips for Field Emission by Reactive-Ion Etching}, series = {Advances in Materials Science and Engineering. Special issue: Advances in Smart Materials and Applications}, volume = {2014}, journal = {Advances in Materials Science and Engineering. Special issue: Advances in Smart Materials and Applications}, publisher = {Hindawi}, issn = {1687-8442}, doi = {10.1155/2014/948708}, pages = {1 -- 6}, abstract = {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.}, language = {en} } @inproceedings{ŁawrowskiPrommesbergerLangeretal., author = {Ławrowski, Robert Damian and Prommesberger, Christian and Langer, Christoph and Dams, Florian and Schreiner, Rupert}, title = {Influence of reactive ion etching parameters on the geometry of silicon tip cathodes for field emission}, series = {Applied Research Conference 2013, ARC 2013 : 17th and 18th October 2013, Deggendorf}, booktitle = {Applied Research Conference 2013, ARC 2013 : 17th and 18th October 2013, Deggendorf}, publisher = {Shaker}, address = {Aachen}, isbn = {978-3-8440-2274-2}, pages = {67 -- 69}, language = {en} } @incollection{ŁawrowskiPrommesbergerLangeretal., author = {Ławrowski, Robert Damian and Prommesberger, Christian and Langer, Christoph and Dams, Florian and Schreiner, Rupert}, title = {Feldemissionselektronenquellen basierend auf Siliziumemittern mit hohen Aspektverh{\"a}ltnis}, series = {Forschungsbericht der OTH Regensburg 2013}, booktitle = {Forschungsbericht der OTH Regensburg 2013}, address = {Regensburg}, pages = {47 -- 48}, language = {de} } @article{LindnerPipaBrandenburgetal., author = {Lindner, Matthias and Pipa, Andrei V. and Brandenburg, Ronny and Schreiner, Rupert}, title = {Expansion of surface barrier discharge scrutinized}, series = {Plasma Sources Science and Technology}, volume = {31}, journal = {Plasma Sources Science and Technology}, number = {10}, publisher = {IOP Publishing}, doi = {10.1088/1361-6595/ac95bf}, abstract = {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. …}, language = {en} } @inproceedings{MingelsBornmannLuetzenkirchenHechtetal., author = {Mingels, Stephan and Bornmann, Benjamin and L{\"u}tzenkirchen-Hecht, Dirk and M{\"u}ller, G{\"u}nter and Langer, Christoph and Prommesberger, Christian and Schreiner, Rupert}, title = {Electric Field Dependence of Photoemission from n- and p-type Si Crystals}, series = {Proceedings, 35th International Free Electron Laser Conference (FEL 2013) : New York, NY, USA, August 26-19, 2013}, booktitle = {Proceedings, 35th International Free Electron Laser Conference (FEL 2013) : New York, NY, USA, August 26-19, 2013}, editor = {Scholl, Caitlin and Schaa, Volker R.W.}, publisher = {Curran}, address = {Red Hook, NY}, isbn = {9783954501267}, pages = {339 -- 343}, abstract = {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.}, language = {en} } @inproceedings{SchreinerPrommesbergerLangeretal., author = {Schreiner, Rupert and Prommesberger, Christian and Langer, Christoph and Dams, Florian and Serbun, Pavel and Bornmann, Benjamin and Navitski, Aliaksandr and M{\"u}ller, G{\"u}nter}, title = {Highly uniform and stable electron field emission from B-doped Si-tip arrays for applications in integrated vacuum microelectronic devices}, series = {25th International Vacuum Nanoelectronics Conference (IVNC) - Jeju, Korea (South), 09.07. - 13.07.2012}, booktitle = {25th International Vacuum Nanoelectronics Conference (IVNC) - Jeju, Korea (South), 09.07. - 13.07.2012}, publisher = {IEEE}, address = {Piscataway, NJ.}, isbn = {978-1-4673-1984-3}, issn = {2380-6311}, doi = {10.1109/IVNC.2012.6316857}, pages = {1 -- 2}, abstract = {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.}, language = {en} } @inproceedings{SchreinerDamsPrommesbergeretal., author = {Schreiner, Rupert and Dams, Florian and Prommesberger, Christian and Bornmann, Benjamin and Serbun, Pavel and Navitski, Aliaksandr and M{\"u}ller, G{\"u}nter}, title = {Silicon-based integrated field emission electron sources for sensor application}, series = {24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Wuppertal, Germany}, booktitle = {24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Wuppertal, Germany}, publisher = {IEEE}, address = {Piscataway, NJ}, pages = {19 -- 20}, abstract = {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.}, language = {en} } @inproceedings{BornmannMingelsSerbunetal., author = {Bornmann, Benjamin and Mingels, Stephan and Serbun, Pavel and L{\"u}tzenkirchen-Hecht, Dirk and M{\"u}ller, G{\"u}nter and Prommesberger, Christian and Langer, Christoph and Dams, Florian and Schreiner, Rupert}, title = {Photosensitivity of electron field emission from B-doped Si-tip arrays}, series = {25th International Vacuum Nanoelectronics Conference (IVNC) ; Jeju, Korea (South), 09.07.2012 - 13.07.2012}, booktitle = {25th International Vacuum Nanoelectronics Conference (IVNC) ; Jeju, Korea (South), 09.07.2012 - 13.07.2012}, publisher = {IEEE}, isbn = {978-1-4673-1984-3}, issn = {2380-6311}, doi = {10.1109/IVNC.2012.6316980}, pages = {1 -- 2}, abstract = {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.}, language = {en} } @inproceedings{LangerPrommesbergerDamsetal., author = {Langer, Christoph and Prommesberger, Christian and Dams, Florian and Serbun, Pavel and Bornmann, Benjamin and Mingels, Stephan and M{\"u}ller, G{\"u}nter and Schreiner, Rupert}, title = {Si-Feldemissionskathoden f{\"u}r Anwendungen in miniaturisierten Ionisationsvakuumsensoren}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft e.V. (DPG), Regensburg, 10. - 15. M{\"a}rz 2013}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft e.V. (DPG), Regensburg, 10. - 15. M{\"a}rz 2013}, publisher = {Deutsche Physikalische Gesellschaft e.V.}, abstract = {Feldemissionselektronenquellen sind aufgrund ihrer prinzipiellen Vorteile gegen{\"u}ber Gl{\"u}hkathoden bereits seit l{\"a}ngerer Zeit Gegenstand der Forschung und werden bisher nur in einigen Spezialanwendungen erfolgreich eingesetzt. Hierbei werden Einzelspitzen mit Spannungen im kV-Bereich und Str{\"o}men im nA-Bereich betrieben. Dagegen werden f{\"u}r miniaturisierte Sensorsysteme eher Spannungen von ca. 100 V und Str{\"o}me von ca. 1 mA ben{\"o}tigt. Dazu wurden bisher meist Feldemissionskathoden mit CNTs vorgeschlagen, welche f{\"u}r Anwendungen in der Halbleiterindustrie aufgrund des Kohlenstoffanteils nicht erw{\"u}nscht 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 S{\"a}ttigungsbereich bei Emissionsstr{\"o}men von ca. 10 nA pro Spitze zeitlich stabil (Schwankungen < 5 \%) und optisch schaltbar (Faktor > 2.5) ist [2].}, language = {de} } @article{BornmannMingelsDamsetal., author = {Bornmann, Benjamin and Mingels, Stephan and Dams, Florian and Prommesberger, Christian and Schreiner, Rupert and L{\"u}tzenkirchen-Hecht, Dirk and M{\"u}ller, G{\"u}nter}, title = {Electron spectrometer in adjustable triode configuration for photo-induced field emission measurements}, series = {The Review of scientific instruments}, volume = {83}, journal = {The Review of scientific instruments}, number = {1}, publisher = {American Institute of Physics}, address = {Melville, NY}, doi = {10.1063/1.3673475}, abstract = {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.}, language = {en} } @inproceedings{BornmannMingelsLuetzenkirchenHechtetal., author = {Bornmann, Benjamin and Mingels, Stephan and L{\"u}tzenkirchen-Hecht, Dirk and M{\"u}ller, G{\"u}nter and Dams, Florian and Schreiner, Rupert}, title = {Field emission spectroscopy studies on photo-sensitive p-doped Si-tip arrays}, series = {24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Historische Stadthalle Wuppertal, Germany}, booktitle = {24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Historische Stadthalle Wuppertal, Germany}, publisher = {IEEE}, isbn = {978-3-00-035081-8}, issn = {2380-6311}, pages = {101 -- 102}, abstract = {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.}, language = {en} } @inproceedings{PrommesbergerDamsLangeretal., author = {Prommesberger, Christian and Dams, Florian and Langer, Christoph and Schreiner, Rupert and Rutkowski, S. and Bornmann, Benjamin and M{\"u}ller, G{\"u}nter}, title = {Simulation of electron trajectories of a field emission electron source in triode configuration by using finite element methods}, series = {24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Historische Stadthalle Wuppertal, Germany}, booktitle = {24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Historische Stadthalle Wuppertal, Germany}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-3-00-035081-8}, issn = {2380-6311}, pages = {144 -- 145}, abstract = {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\%.}, language = {en} } @misc{WeberDendorferSuessetal., author = {Weber, Karsten and Dendorfer, Sebastian and S{\"u}ß, Franz and Kubowitsch, Simone and Schratzenstaller, Thomas and Haug, Sonja and Mohr, Christa and Kiesl, Hans and Drechsler, J{\"o}rg and Westner, Markus and Kobus, J{\"o}rn and Schubert, Martin J. W. and Zenger, Stefan and Pietsch, Alexander and Weiß, Josef and Hinterseer, Sebastian and Schieck, Roland and Scherzinger, Stefanie and Klettke, Meike and Ringlstetter, Andreas and St{\"o}rl, Uta and Bissyand{\´e}, Tegawend{\´e} F. and Seeburger, Achim and Schindler, Timo and Ramsauer, Ralf and Kiszka, Jan and K{\"o}lbl, Andreas and Lohmann, Daniel and Mauerer, Wolfgang and Maier, Johannes and Scorna, Ulrike and Palm, Christoph and Soska, Alexander and Mottok, J{\"u}rgen and Ellermeier, Andreas and V{\"o}gele, Daniel and Hierl, Stefan and Briem, Ulrich and Buschmann, Knut and Ehrlich, Ingo and Pongratz, Christian and Pielmeier, Benjamin and Tyroller, Quirin and Monkman, Gareth J. and Gut, Franz and Roth, Carina and Hausler, Peter and Bierl, Rudolf and Prommesberger, Christian and Ławrowski, Robert Damian and Langer, Christoph and Schreiner, Rupert and Huang, Yifeng and She, Juncong and Ottl, Andreas and Rieger, Walter and Kraml, Agnes and Poxleitner, Thomas and Hofer, Simon and Heisterkamp, Benjamin and Lerch, Maximilian and Sammer, Nike and Golde, Olivia and Wellnitz, Felix and Schmid, Sandra and Muntschick, Claudia and Kusterle, Wolfgang and Paric, Ivan and Br{\"u}ckl, Oliver and Haslbeck, Matthias and Schmidt, Ottfried and Schwanzer, Peter and Rabl, Hans-Peter and Sterner, Michael and Bauer, Franz and Steinmann, Sven and Eckert, Fabian and Hofrichter, Andreas}, title = {Forschungsbericht 2017}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-3-5}, doi = {10.35096/othr/pub-1383}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13835}, subject = {Forschung}, language = {de} } @inproceedings{BachmannDamsDuesbergetal., author = {Bachmann, Michael and Dams, Florian and D{\"u}sberg, F. and Hofmann, Martin and Pahlke, Andreas and Langer, Christoph and Ławrowski, Robert Damian and Prommesberger, Christian and Schreiner, Rupert}, title = {Stability investigation of high aspect ratio n-type silicon field emitter arrays}, series = {2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China}, booktitle = {2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China}, publisher = {IEEE}, doi = {10.1109/IVNC.2015.7225584}, pages = {204 -- 205}, abstract = {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.}, language = {en} } @inproceedings{SerbunNavitskiMuelleretal., author = {Serbun, Pavel and Navitski, Aliaksandr and M{\"u}ller, G{\"u}nter and Schreiner, Rupert and Prommesberger, Christian and Langer, Christoph and Dams, Florian}, title = {Scaling of the field emission current from B-doped Si-tip arrays}, series = {25th International Vacuum Nanoelectronics Conference (IVNC) ; Jeju, Korea (South), 09.07.2012 - 13.07.2012}, booktitle = {25th International Vacuum Nanoelectronics Conference (IVNC) ; Jeju, Korea (South), 09.07.2012 - 13.07.2012}, publisher = {IEEE}, address = {Piscataway, N.J.}, isbn = {978-1-4673-1984-3}, issn = {2380-6311}, doi = {10.1109/IVNC.2012.6316965}, pages = {1 -- 2}, abstract = {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.}, language = {en} } @article{ŁawrowskiPirkerKanekoetal., author = {Ławrowski, Robert Damian and Pirker, Luka and Kaneko, Keita and Kokubo, Hiroki and Bachmann, Michael and Ikuno, Takashi and Remskar, Maja and Schreiner, Rupert}, title = {Field emission from nanotubes and flakes of transition metal dichalcogenides}, series = {Journal of Vacuum Science and Technology B}, volume = {38}, journal = {Journal of Vacuum Science and Technology B}, number = {3}, publisher = {AIP Publishing}, doi = {10.1116/1.5140474}, pages = {032801}, abstract = {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.}, language = {en} } @article{KleshchSerbunLuetzenkirchenHechtetal., author = {Kleshch, Victor I. and Serbun, Pavel and L{\"u}tzenkirchen-Hecht, Dirk and Orekhov, Anton and Ivanov, Victor E. and Prommesberger, Christian and Langer, Christoph and Schreiner, Rupert and Obraztsov, Alexander N.}, title = {A Comparative Study of Field Emission from Pristine, Ion-treated and Tungsten Nanoparticle-decorated p-type Silicon Tips}, series = {Physica Status Solidi B}, volume = {256}, journal = {Physica Status Solidi B}, number = {9}, publisher = {Wiley}, doi = {10.1002/pssb.201800646}, abstract = {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.}, language = {en} } @inproceedings{SerbunPorshynMuelleretal., author = {Serbun, Pavel and Porshyn, Vitali and M{\"u}ller, G{\"u}nter and L{\"u}tzenkirchen-Hecht, Dirk and Prommesberger, Christian and Langer, Christoph and Ławrowski, Robert Damian and Schreiner, Rupert}, title = {Field emission behavior of single n- and p-type black Si pillar structures}, series = {International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan}, booktitle = {International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan}, publisher = {IEEE}, doi = {10.1109/IVNC.2018.8520292}, pages = {1-2}, abstract = {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.}, language = {en} } @article{MingelsPorshynPrommesbergeretal., author = {Mingels, Stephan and Porshyn, Vitali and Prommesberger, Christian and Langer, Christoph and Schreiner, Rupert and L{\"u}tzenkirchen-Hecht, Dirk and M{\"u}ller, G{\"u}nter}, title = {Photosensitivity of p-type black Si field emitter arrays}, series = {Journal of Applied Physics}, volume = {119}, journal = {Journal of Applied Physics}, number = {16}, doi = {10.1063/1.4948328}, abstract = {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.}, language = {en} } @inproceedings{SerbunPorshynMuelleretal., author = {Serbun, Pavel and Porshyn, Vitali and M{\"u}ller, G{\"u}nter and Mingels, Stephan and L{\"u}tzenkirchen-Hecht, Dirk and Bachmann, Michael and D{\"u}sberg, Felix and Dams, Florian and Hofmann, Martin and Pahlke, Andreas and Prommesberger, Christian and Langer, Christoph and Ławrowski, Robert Damian and Schreiner, Rupert}, title = {Field emission behavior of Au-tip-coated p-type Si pillar structures}, series = {29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada}, booktitle = {29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada}, publisher = {IEEE}, issn = {2380-6311}, doi = {10.1109/IVNC.2016.7551516}, pages = {181 -- 182}, abstract = {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.}, language = {en} } @inproceedings{SerbunPorshynLuetzenkirchenHechtetal., author = {Serbun, Pavel and Porshyn, Vitali and L{\"u}tzenkirchen-Hecht, Dirk and Prommesberger, Christian and Langer, Christoph and Ławrowski, Robert Damian and Schreiner, Rupert}, title = {Photosensitivity of single silicon high-aspect-ratio tips with different doping levels}, series = {International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan}, booktitle = {International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan}, publisher = {IEEE}, doi = {10.1109/IVNC.2018.8520288}, pages = {1-2}, abstract = {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.}, language = {en} } @inproceedings{SchreinerLangerPrommesbergeretal., author = {Schreiner, Rupert and Langer, Christoph and Prommesberger, Christian and Ławrowski, Robert Damian and Dams, Florian and Bachmann, Michael and D{\"u}sberg, F. and Hofmann, Martin and Pahlke, Andreas and Serbun, Pavel and Mingels, Stephan and M{\"u}ller, G{\"u}nter}, title = {Semiconductor field emission electron sources using a modular system concept for application in sensors and x-ray-sources}, series = {2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China}, booktitle = {2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China}, publisher = {IEEE}, doi = {10.1109/IVNC.2015.7225572}, pages = {178 -- 179}, abstract = {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.}, language = {en} } @inproceedings{ŁawrowskiLangerPrommesbergeretal., author = {Ławrowski, Robert Damian and Langer, Christoph and Prommesberger, Christian and Schreiner, Rupert and Mingels, Stephan and Porshyn, Vitali and Serbun, Pavel and M{\"u}ller, G{\"u}nter}, title = {Field emission from surface textured GaN with buried double-heterostructures}, series = {2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China}, booktitle = {2015 28th International Vacuum Nanoelectronics Conference (IVNC), 13-17 July 2015, Guangzhou, China}, publisher = {IEEE}, doi = {10.1109/IVNC.2015.7225548}, pages = {106 -- 107}, abstract = {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.}, language = {en} } @inproceedings{MingelsPorshynSerbunetal., author = {Mingels, Stephan and Porshyn, Vitali and Serbun, Pavel and L{\"u}tzenkirchen-Hecht, Dirk and M{\"u}ller, G{\"u}nter and Prommesberger, Christian and Langer, Christoph and Schreiner, Rupert and Lutzenkirchen-Hecht, Dirk}, title = {Photo-enhanced field emission properties of p-doped black Si arrays}, series = {2016 29th International Vacuum Nanoelectronics Conference (IVNC), 11-15 July 2016, Vancouver, BC, Canada}, booktitle = {2016 29th International Vacuum Nanoelectronics Conference (IVNC), 11-15 July 2016, Vancouver, BC, Canada}, publisher = {IEEE}, doi = {10.1109/IVNC.2016.7551447}, pages = {1 -- 2}, abstract = {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.}, language = {en} } @inproceedings{SchreinerLangerPrommesbergeretal., author = {Schreiner, Rupert and Langer, Christoph and Prommesberger, Christian and Mingels, Stephan and Serbun, Pavel and M{\"u}ller, G{\"u}nter}, title = {Field emission from surface textured extraction facets of GaN light emitting diodes}, series = {26th International Vacuum Nanoelectronics Conference (IVNC), 8-12 July 2013, Roanoke, VA, USA}, booktitle = {26th International Vacuum Nanoelectronics Conference (IVNC), 8-12 July 2013, Roanoke, VA, USA}, publisher = {IEEE}, doi = {10.1109/ivnc.2013.6624721}, abstract = {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 ({\O}anode= 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.}, language = {en} } @inproceedings{NavitskiSerbunMuelleretal., author = {Navitski, Aliaksandr and Serbun, Pavel and M{\"u}ller, G{\"u}nter and Schreiner, Rupert and Dams, Florian}, title = {Efficient and reliable field emission from silicon tip arrays for miniaturized electron sources}, series = {2011 24th International Vacuum Nanoelectronics Conference ; 18-22 July 2011 Wuppertal}, booktitle = {2011 24th International Vacuum Nanoelectronics Conference ; 18-22 July 2011 Wuppertal}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-3-00-035081-8}, issn = {2380-6311}, pages = {71 -- 72}, abstract = {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.}, language = {en} } @article{PirkerŁawrowskiSchreineretal., author = {Pirker, Luka and Ławrowski, Robert Damian and Schreiner, Rupert and Remškar, Maja and Višić, Bojana}, title = {MoₓWₓ₋₁S₂ Nanotubes for Advanced Field Emission Application}, series = {Advanced Functional Materials}, journal = {Advanced Functional Materials}, publisher = {Wiley}, issn = {1616-3028}, doi = {10.1002/adfm.202213869}, pages = {1 -- 8}, abstract = {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.}, language = {en} } @misc{BroserFalterŁawrowskietal., author = {Broser, Christian and Falter, Thomas and Ławrowski, Robert Damian and Altenbuchner, Amelie and V{\"o}gele, Daniel and Koss, Claus and Schlamp, Matthias and Dunnweber, Jan and Steffens, Oliver and Heckner, Markus and Jaritz, Sabine and Schiegl, Thomas and Corsten, Sabine and Lauer, Norina and Guertler, Katherine and Koenig, Eric and Haug, Sonja and Huber, Dominik and Birkenmaier, Clemens and Krenkel, Lars and Wagner, Thomas and Justus, Xenia and Saßmannshausen, Sean Patrick and Kleine, Nadine and Weber, Karsten and Braun, Carina N. and Giacoppo, Giuliano and Heinrich, Michael and Just, Tobias and Schreck, Thomas and Schnabl, Andreas and Gilmore, Amador T{\´e}ran and Roeslin, Samuel and Schmid, Sandra and Wellnitz, Felix and Malz, Sebastian and Maurial, Andreas and Hauser, Florian and Mottok, J{\"u}rgen and Klettke, Meike and Scherzinger, Stefanie and St{\"o}rl, Uta and Heckner, Markus and Bazo, Alexander and Wolff, Christian and Kopper, Andreas and Westner, Markus and Pongratz, Christian and Ehrlich, Ingo and Briem, Ulrich and Hederer, Sebastian and Wagner, Marcus and Schillinger, Moritz and G{\"o}rlach, Julien and Hierl, Stefan and Siegl, Marco and Langer, Christoph and Hausladen, Matthias and Schreiner, Rupert and Haslbeck, Matthias and Kreuzer, Reinhard and Br{\"u}ckl, Oliver and Dawoud, Belal and Rabl, Hans-Peter and Gamisch, Bernd and Schmidt, Ottfried and Heberl, Michael and G{\"a}nsbauer, Bianca and Bick, Werner and Ellermeier, Andreas and Monkman, Gareth J. and Prem, Nina and Sindersberger, Dirk and Tschurtschenthaler, Karl and Aurbach, Maximilian and Dendorfer, Sebastian and Betz, Michael A. and Szecsey, Tamara and Mauerer, Wolfgang and Murr, Florian}, title = {Forschung 2018}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-5-9}, doi = {10.35096/othr/pub-1382}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13826}, pages = {98}, subject = {Forschung}, language = {de} } @misc{RueckBierlLechneretal., author = {R{\"u}ck, Thomas and Bierl, Rudolf and Lechner, Alfred and Graf, Antonia and Dams, Florian and Schreiner, Rupert and Auchter, Eberhard and Kriz, Willy and Deubzer, MIchael and Schiller, Frank and Mottok, J{\"u}rgen and Niemetz, Michael and Margull, Ulrich and Hagel, Georg and Utesch, Matthias and Waldherr, Franz and B{\"o}hm, Matthias and Fraunhoffer, Judith and Gardeia, Armin and Schneider, Ralph and Streubel, Janet and Landes, Dieter and Studt, Reimer and Peuker, Dominik and Scharfenberg, Georg and Hook, Christian and Schuster, Dietwald and Ehrlich, Ingo and Dinnebier, Heinrich and Briem, Ulrich and L{\"a}mmlein, Stephan and Koder, Alexander and Bialek, Adam and Genewsky, Axel and Neumeier, Michael and Schlosser, Philipp and Rabl, Hans-Peter and Paule, Matthias and Galster, Christoph and Schiedermeier, Michael and Zwickel, Andreas and Hobmeier, Christoph and Bischoff, Tobias and Rill, Georg and Schaeffer, Thomas and Arbesmeier, Martin and Groß, Andreas and Schlegl, Thomas and Becker, Mark and Senn, Konrad and Schliekmann, Claus and Scholz, Peter and Sippl, Christian and Grill, Martin}, title = {Forschungsbericht 2011 / Hochschule f{\"u}r Angewandte Wissenschaften - Fachhochschule Regensburg}, editor = {Eckstein, Josef}, address = {Regensburg}, organization = {Hochschule f{\"u}r Angewandte Wissenschaften Regensburg}, issn = {1868-3533}, doi = {10.35096/othr/pub-732}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7321}, language = {de} } @inproceedings{HerdlBachmannWohlfartsstaetteretal., author = {Herdl, Florian and Bachmann, Michael and Wohlfartsst{\"a}tter, Dominik and D{\"u}sberg, Felix and Dudeck, Markus and Eder, Magdalena and Meyer, Manuel and Pahlke, Andreas and Edler, Simon and Schels, Andreas and Hansch, Walter and Schreiner, Rupert and Wohlfartsstatter, Dominik and Dusberg, Felix}, title = {A novel current dependent field emission performance test}, series = {2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France}, booktitle = {2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France}, doi = {10.1109/IVNC52431.2021.9600695}, pages = {1 -- 2}, abstract = {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.}, language = {en} } @inproceedings{BiekerRoustaieSchlaaketal., author = {Bieker, Johannes and Roustaie, Farough and Schlaak, Helmut F. and Langer, Christoph and Schreiner, Rupert}, title = {Field emission characterization of in-situ deposited metallic nanocones}, series = {2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany}, booktitle = {2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany}, publisher = {IEEE}, doi = {10.1109/IVNC.2017.8051571}, pages = {120 -- 121}, abstract = {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.}, language = {en} } @inproceedings{SchelsEdlerHanschetal., author = {Schels, Andreas and Edler, Simon and Hansch, Walter and Bachmann, Michael and Herdl, Florian and Dusberg, F. and Eder, Magdalena and Meyer, Manuel and Dudek, M. and Pahlke, Andreas and Schreiner, Rupert}, title = {Current dependent performance test used on different types of silicon field emitter arrays}, series = {2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France}, booktitle = {2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France}, editor = {Purcell, Stephen and Mazellier, Jean-Paul}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-6654-2589-6}, doi = {10.1109/IVNC52431.2021.9600787}, pages = {1 -- 2}, abstract = {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.}, language = {en} } @article{SchelsHerdlHausladenetal., author = {Schels, Andreas and Herdl, Florian and Hausladen, Matthias and Wohlfartsst{\"a}tter, Dominik and Edler, Simon and Bachmann, Michael and Pahlke, Andreas and Schreiner, Rupert and Hansch, Walter}, title = {Quantitative Field Emission Imaging for Studying the Doping-Dependent Emission Behavior of Silicon Field Emitter Arrays}, series = {Micromachines}, volume = {14}, journal = {Micromachines}, number = {11}, publisher = {MDPI}, doi = {10.3390/mi14112008}, abstract = {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.}, language = {en} } @inproceedings{SchelsHerdlHausladenetal., author = {Schels, Andreas and Herdl, Florian and Hausladen, Matthias and Wohlfartsst{\"a}tter, Dominik and Bachmann, Michael and Edler, Simon and D{\"u}sberg, Felix and Pahlke, Andreas and Buchner, Philipp and Schreiner, Rupert and Hansch, Walter}, title = {Beta Factor Mapping of Individual Emitting Tips During Integral Operation of Field Emission Arrays}, series = {2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA}, booktitle = {2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA}, publisher = {IEEE}, isbn = {979-8-3503-0143-4}, doi = {10.1109/IVNC57695.2023.10188957}, pages = {224 -- 226}, abstract = {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.}, language = {en} } @inproceedings{HerdlKueddelsmannSchelsetal., author = {Herdl, Florian and Kueddelsmann, Maximillian J. and Schels, Andreas and Bachmann, Michael and Edler, Simon and Wohlfartsst{\"a}tter, Dominik and D{\"u}sberg, Felix and Prugger, Alexander and Dillig, Michael and Dams, Florian and Schreiner, Rupert and Coile{\´a}in, Cormac {\´O}. and Zimmermann, Stefan and Pahlke, Andreas and Duesberg, Georg S.}, title = {Characterization and Operation of Graphene-Oxide-Semiconductor Emitters at Atmospheric Pressure Levels}, series = {2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA}, booktitle = {2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA}, publisher = {IEEE}, isbn = {979-8-3503-0143-4}, doi = {10.1109/IVNC57695.2023.10188974}, pages = {14 -- 16}, abstract = {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.}, language = {en} } @inproceedings{HausladenBuchnerSchelsetal., author = {Hausladen, Matthias and Buchner, Philipp and Schels, Andreas and Edler, Simon and Bachmann, Michael and Schreiner, Rupert}, title = {An Integrated Field Emission Electron Source on a Chip Fabricated by Laser-Micromachining and Mems Technology}, series = {2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA}, booktitle = {2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA}, publisher = {IEEE}, isbn = {979-8-3503-0143-4}, doi = {10.1109/IVNC57695.2023.10189001}, pages = {115 -- 116}, abstract = {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.}, language = {en} } @inproceedings{BuchnerHausladenSchelsetal., author = {Buchner, Philipp and Hausladen, Matthias and Schels, Andreas and Herdl, Florian and Edler, Simon and Bachmann, Michael and Schreiner, Rupert}, title = {An Integrated Silicon Nanowire Field Emission Electron Source on a Chip with High Electron Transmission}, series = {2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA}, booktitle = {2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA}, publisher = {IEEE}, isbn = {979-8-3503-0143-4}, doi = {10.1109/IVNC57695.2023.10188878}, pages = {6 -- 8}, abstract = {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.}, language = {en} } @inproceedings{HausladenSchelsBuchneretal., author = {Hausladen, Matthias and Schels, Andreas and Buchner, Philipp and Bartl, Mathias and Asgharzade, Ali and Edler, Simon and Wohlfartsst{\"a}tter, Dominik and Bachmann, Michael and Schreiner, Rupert}, title = {Improved Method for Determining the Distribution of FEA Currents by Optical CMOS Sensors}, series = {37th International Vacuum Nanoelectronics Conference (IVNC), 15-19 July 2024, Brno, Czech Republic}, booktitle = {37th International Vacuum Nanoelectronics Conference (IVNC), 15-19 July 2024, Brno, Czech Republic}, publisher = {IEEE}, doi = {10.1109/IVNC63480.2024.10652543}, pages = {1 -- 2}, abstract = {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.}, language = {en} } @article{BachmannDuesbergPahlkeetal., author = {Bachmann, Michael and D{\"u}sberg, Felix and Pahlke, Andreas and Edler, Simon and Schels, Andreas and Herdl, Florian and Hausladen, Matthias and Buchner, Philipp and Schreiner, Rupert}, title = {The "LED-version" of the electron gun: An electron source for operation in ambient pressure environments based on silicon field emitter arrays}, series = {Vakuum in Forschung und Praxis}, volume = {35}, journal = {Vakuum in Forschung und Praxis}, number = {3}, publisher = {Wiley}, doi = {10.1002/vipr.202300801}, pages = {32 -- 37}, abstract = {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.}, language = {en} } @article{HausladenSchelsBuchneretal., author = {Hausladen, Matthias and Schels, Andreas and Buchner, Philipp and Bartl, Mathias and Asgharzade, Ali and Edler, Simon and Wohlfartsst{\"a}tter, Dominik and Bachmann, Michael and Schreiner, Rupert}, title = {Measurement of field emission array current distributions by metal-coated CMOS image sensors}, series = {Journal of Vacuum Science \& Technology B}, volume = {42}, journal = {Journal of Vacuum Science \& Technology B}, number = {6}, publisher = {AIP Publishing}, doi = {10.1116/6.0004074}, abstract = {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.}, language = {en} } @article{SchreinerWiedmannCoenningetal., author = {Schreiner, Rupert and Wiedmann, J. and Coenning, W. and Porsche, J. and Gentner, Jean-Louis and Berroth, Manfred and Scholz, Ferdinand and Schweizer, H.}, title = {Fabrication approach for antiphase narrow linewidth complex coupled 1.55 μm DFB lasers}, series = {Electronics Letters}, volume = {35}, journal = {Electronics Letters}, number = {2}, publisher = {The Institution of Engineering and Technology IET}, issn = {0013-5194}, doi = {10.1049/el:19990132}, pages = {146 -- 148}, abstract = {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.}, language = {en} } @article{HausladenSchelsAsgharzadeetal., author = {Hausladen, Matthias and Schels, Andreas and Asgharzade, Ali and Buchner, Philipp and Bartl, Mathias and Wohlfartsst{\"a}tter, Dominik and Edler, Simon and Bachmann, Michael and Schreiner, Rupert}, title = {Investigation of Influencing Factors on the Measurement Signal of a CMOS Image Sensor for Measuring Field Emission Currents}, series = {Sensors}, volume = {25}, journal = {Sensors}, number = {5}, publisher = {MDPI}, doi = {10.3390/s25051529}, pages = {17}, language = {en} } @inproceedings{ŁawrowskiLangerSchreineretal., author = {Ławrowski, Robert Damian and Langer, Christoph and Schreiner, Rupert and Sellmair, Josef}, title = {Nano Emitters on Silicon Pillar Structures generated by a Focused Electron Beam Induced Deposition}, series = {International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan}, booktitle = {International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan}, publisher = {IEEE}, doi = {10.1109/IVNC.2018.8520059}, pages = {1-2}, abstract = {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.}, language = {en} } @inproceedings{BuchnerHausladenBartletal., author = {Buchner, Philipp and Hausladen, Matthias and Bartl, Mathias and Schreiner, Rupert}, title = {Elektronenquellen basierend auf Feldemission aus Silizium}, series = {Tagungsband zum 4. Symposium Elektronik und Systemintegration ESI: 17. April 2024, Hochschule Landshut}, booktitle = {Tagungsband zum 4. Symposium Elektronik und Systemintegration ESI: 17. April 2024, Hochschule Landshut}, publisher = {Hochschule f{\"u}r Angewandte Wissenschaften Landshut}, address = {Landshut}, isbn = {978-3-9818439-9-6}, doi = {10.57688/421}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:860-opus4-4212}, pages = {46 -- 53}, abstract = {Der Beitrag gibt einen {\"U}berblick {\"u}ber zwei typische Bauformen f{\"u}r Elektronenquellen auf der Basis von Feldemission aus Silizium. Des Weiteren wird eine typische Trioden-Beschaltung solcher Elektronenquellen f{\"u}r hohe Elektronentransmission vorgestellt und dabei auf ihre Leistungsf{\"a}higkeit eingegangen.}, language = {de} } @article{EilerWeberGerlesbergeretal., author = {Eiler, Julian and Weber, Stefan and Gerlesberger, Peter and Pl{\"o}chinger, Heinz and Schreiner, Rupert}, title = {Active heat-loss compensated miniaturized pirani sensor chip}, series = {IEEE Sensors Letters}, volume = {9}, journal = {IEEE Sensors Letters}, number = {10}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, issn = {2475-1472}, doi = {10.1109/LSENS.2025.3605747}, pages = {4}, abstract = {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.}, language = {en} } @misc{EilerWeberGerlesbergeretal., author = {Eiler, Julian and Weber, Stefan and Gerlesberger, Peter and Pl{\"o}chinger, Heinz and Schreiner, Rupert}, title = {Miniaturized Pirani vacuum sensor with active heat-loss compensation}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft e.V. (DPG), Regensburg, 16. - 21. M{\"a}rz 2025}, journal = {Verhandlungen der Deutschen Physikalischen Gesellschaft e.V. (DPG), Regensburg, 16. - 21. M{\"a}rz 2025}, publisher = {Deutsche Physikalische Gesellschaft e.V.}, issn = {2751-0522}, abstract = {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.}, language = {en} } @inproceedings{EilerBerndtSchreiner, author = {Eiler, Julian and Berndt, Dominik and Schreiner, Rupert}, title = {Miniaturisierter Wasserstoffsensor basierend auf der 3-Omega Methode}, series = {Tagungsband zum 4. Symposium Elektronik und Systemintegration ESI: 17. April 2024, Hochschule Landshut}, booktitle = {Tagungsband zum 4. Symposium Elektronik und Systemintegration ESI: 17. April 2024, Hochschule Landshut}, publisher = {Hochschule f{\"u}r Angewandte Wissenschaften Landshut}, address = {Landshut}, isbn = {978-3-9818439-9-6}, doi = {10.57688/420}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:860-opus4-4205}, pages = {38 -- 45}, abstract = {Die Arbeit stellt einen thermischen Wasserstoffsensor auf Siliziumbasis vor, der mit der 3-Omega Messmethode betrieben wird. Durch das dynamische Messverfahren, die große Sensoroberfl{\"a}che bei gleichzeitig geringer thermischer Masse und der Materialkombination wird eine Aufl{\"o}sungsgrenze von 55 ppm Wasserstoff in Stickstoff erreicht.}, language = {de} } @misc{KrysztofBaranowskiZychlaetal., author = {Krysztof, Michal and Baranowski, Kamil and Zychla, Michal and Hausladen, Matthias and Schreiner, Rupert and Kn{\´a}pek, Aleksandr}, title = {MP61 - Detection of Electron Beam in Atmospheric Pressure Using CMOS Image Sensor}, series = {EUROSENSORS XXXVII ; 07.09.2025 - 10.09.2025 ; Wroclaw ; Poster I}, journal = {EUROSENSORS XXXVII ; 07.09.2025 - 10.09.2025 ; Wroclaw ; Poster I}, publisher = {AMA}, doi = {10.5162/EUROSENSORS2025/MP61}, pages = {325 -- 326}, abstract = {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.}, language = {en} }