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 - 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 - 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 - 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 -