@article{SerbunBornmannNavitskietal., author = {Serbun, Pavel and Bornmann, Benjamin and Navitski, Aliaksandr and M{\"u}ller, G{\"u}nter and Prommesberger, Christian and Langer, Christoph and Dams, Florian and Schreiner, Rupert}, title = {Stable field emission of single B-doped Si tips and linear current scaling of uniform tip arrays for integrated vacuum microelectronic devices}, series = {Journal of Vacuum Science \& Technology B Nanotechnology and Microelectronics}, volume = {31}, journal = {Journal of Vacuum Science \& Technology B Nanotechnology and Microelectronics}, number = {2}, publisher = {AIP Publishing}, doi = {10.1116/1.4765088}, abstract = {Advanced Si-based semiconductor technology is most suitable to fabricate uniform nanostructures as integrated field emitter arrays for novel vacuum electronic devices. In order to improve the field emission homogeneity and stability of p-type silicon tip arrays for pulsed sensor applications, the authors have systematically studied the influence of the fabrication parameters on the tip shape and on the specific operating conditions. Based on detailed design calculations of the field enhancement, they have fabricated two series of hexagonal arrays of B-doped Si-tips in a triangular arrangement. The first (second) type contains three (four) patches with different number of tips (1, 91, 547 and 1, 19, 1027, 4447 for the first and second type, respectively) of about 1 (2.5) μm height, ∼20 (20) nm apex radius, and 20 (10) μm pitch. The field emission properties of both individual tips and complete arrays were investigated with a field emission scanning microscope at a pressure of 10-9 mbar. The current plateau of these tips typically occurs at about 10 (3) nA and around 65 (25) V/μm field level. In this carrier saturation range, single tips provide the highest current stability (<5\%) and optical current switching ratio (∼2.5). Fairly homogeneous emission of the tip arrays leads to an undershooting of the expected linear scaling of the mean plateau current as well as to a much improved current stability (<1\%).}, language = {en} } @inproceedings{MingelsBornmannLuetzenkirchenHechtetal., author = {Mingels, Stephan and Bornmann, Benjamin and L{\"u}tzenkirchen-Hecht, Dirk and M{\"u}ller, G{\"u}ntner 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{SchreinerLangerPrommesbergeretal., author = {Schreiner, Rupert and Langer, Christoph and Prommesberger, Christian and Mingels, S. and Serbun, Pavel and M{\"u}ller, G{\"u}ntner}, 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{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} } @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}ntner 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} } @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} }