@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{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{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} } @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} } @inproceedings{BartlHausladenAsgharzadeetal., author = {Bartl, Mathias and Hausladen, Matthias and Asgharzade, Ali and Buchner, Philipp and Krysztof, Michal and Kn{\´a}pek, Alexandr and Bachmann, Michael and Schreiner, Rupert}, title = {Experimental method for investigation of the emission pattern characteristics of individual field emission tips using a CMOS image sensor}, series = {38th International Vacuum Nanoelectronics Conference (IVNC)}, booktitle = {38th International Vacuum Nanoelectronics Conference (IVNC)}, publisher = {IEEE}, doi = {10.1109/IVNC65669.2025.11121040}, pages = {2}, abstract = {The emission pattern characteristics of individual silicon field emission tips were investigated using a CMOS image sensor. The quality of the image was improved by spatial and temporal averaging, so that individual emission centers could be identified and their temporal changes investigated. By mapping the emission current onto the image, the distribution of the current density on the image sensor could be calculated.}, language = {en} } @inproceedings{BaranowskiZychlaKrysztofetal., author = {Baranowski, Kamil and Zychla, Michał and Krysztof, Michał and Ż{\´o}łtowski, Michał and Hausladen, Matthias and Schreiner, Rupert and Kn{\´a}pek, Aleksandr}, title = {Experimenal method for studying electron beams in gaseous environments using a CMOS image sensor}, series = {38th International Vacuum Nanoelectronics Conference (IVNC)}, booktitle = {38th International Vacuum Nanoelectronics Conference (IVNC)}, publisher = {IEEE}, isbn = {979-8-3315-3705-0}, doi = {10.1109/IVNC65669.2025.11120851}, pages = {2}, abstract = {Detecting and analyzing electron beams in atmospheric conditions remains a significant challenge due to scattering and absorption of electrons by gas molecules. In this work, a novel approach using a CMOS image sensor for real-time electron beam detection after its transmission through air is presented. The setup enables visualization of beam divergence, emission profiles, and dynamic behavior under atmospheric pressure. Presented results demonstrate the potential of CMOS image sensor for electron beam analysis in gaseous environment.}, language = {en} } @inproceedings{AllahamBurdaKnapeketal., author = {Allaham, Mohammad M. and Burda, Daniel and Kn{\´a}pek, Alexandr and Krysztof, Michał and Baranowski, Kamil and Hausladen, Matthias and Schreiner, Rupert}, title = {Testing the performance of tungsten-graphite cathodes as MEMS Electron microscope electron source}, series = {38th International Vacuum Nanoelectronics Conference (IVNC)}, booktitle = {38th International Vacuum Nanoelectronics Conference (IVNC)}, publisher = {IEEE}, doi = {10.1109/IVNC65669.2025.11121041}, pages = {2}, abstract = {This work presents preliminary results of the performance testing of exfoliated graphene layers deposited on the nanotip of a tungsten field emission cathode. The obtained tungsten-graphite cathodes were then operated in a 3D-printed MEMS electron microscope testing model for later applications. The results were promising, where a maximum emission current of 50.2 μA was obtained with an extraction voltage of 1 kV and anode voltage of 3 kV.}, language = {en} } @inproceedings{AsgharzadeBartlHausladenetal., author = {Asgharzade, Ali and Bartl, Mathias and Hausladen, Matthias and Chen, Yang and Buchner, Philipp and Edler, Simon and Bachmann, Michael and She, Juncong and Schreiner, Rupert}, title = {Investigation on the influence of internal voltage drops on the emission behavior of silicon field emission arrays using CMOS image sensor}, series = {38th International Vacuum Nanoelectronics Conference (IVNC)}, booktitle = {38th International Vacuum Nanoelectronics Conference (IVNC)}, publisher = {IEEE}, doi = {10.1109/IVNC65669.2025.11120937}, pages = {2}, abstract = {In this paper we report on an improved measurement and analysis method for determining the emission current distribution of field emitter arrays with CMOS sensors. It can also be used for field emission arrays where not all surfaces of the emitters are at the same electrical potential (e.g. for p-doped Si tips, where a strong current saturation occurs). To demonstrate the functionality of this method, a n-doped field emission array was measured using a variable external series resistance. Brightness variations in emission spots were analyzed to re-calculate the known series resistances for comparison. The re-calculated value is in good agreement with the actual value of the resistance. This method offers a quantitative approach to assess internal voltage drop effects on field emission using optical readout}, language = {en} } @article{BuchnerHausladenBartletal., author = {Buchner, Philipp and Hausladen, Matthias and Bartl, Mathias and Bachmann, Michael and Schreiner, Rupert}, title = {High current field emission from Si nanowires on pillar structures}, series = {Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics}, volume = {42}, journal = {Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics}, number = {2}, publisher = {AIP}, issn = {2166-2754}, doi = {10.1116/6.0003384}, abstract = {We investigate the influence of the geometry and doping level on the performance of n-type silicon nanowire field emitters on silicon pillar structures. Therefore, multiple cathodes with 50 by 50 pillar arrays (diameter: 5 μm, height: 30 μm, spacing: 50 μm) were fabricated and measured in diode configuration. In the first experiment, we compared two geometry types using the same material. Geometry 1 is black silicon, which is a highly dense surface covering a forest of tightly spaced silicon needles resulting from self-masking during a plasma etching process of single crystal silicon. Geometry 2 are silicon nanowires, which are individual spaced-out nanowires in a crownlike shape resulting from a plasma etching process of single crystal silicon. In the second experiment, we compared two different silicon doping levels [n-type (P), 1-10 and <0.005 Ω cm] for the same geometry. The best performance was achieved with lower doped silicon nanowire samples, emitting 2 mA at an extraction voltage of 1 kV. The geometry/material combination with the best performance was used to assemble an integrated electron source. These electron sources were measured in a triode configuration and reached onset voltages of about 125 V and emission currents of 2.5 mA at extraction voltages of 400 V, while achieving electron transmission rates as high as 85.0\%.}, language = {en} } @inproceedings{BarikRawatMannaetal., author = {Barik, Ranjan Kumar and Rawat, Vikram Singh and Manna, Subhrajit and Bandyopadhyay, Ayan Kumar and Hausladen, Matthias and Asgharzade, Ali and Schreiner, Rupert}, title = {On Chip Electron Gun Design Using Silicon Tip Field Emitter Array}, series = {2025 IEEE Microwaves, Antennas, and Propagation Conference (MAPCON), 14-18. Dezember 2025, Kochi, India}, booktitle = {2025 IEEE Microwaves, Antennas, and Propagation Conference (MAPCON), 14-18. Dezember 2025, Kochi, India}, publisher = {IEEE}, isbn = {979-8-3315-3722-7}, doi = {10.1109/MAPCON65020.2025.11426578}, pages = {4}, abstract = {Silicon based silicon tip array emitter has developed at OTH Regensburg, Germany. This array emitter is the basis for development of a novel electron gun. This field emitter electron sources were fabricated using laser-micromachining technique followed by MEMS technology. In this work, the design and development of electron gun using complete silicon structure is reported. The goal of this work is to develop electron gun using less effort, easy and hassle free technique.}, language = {en} } @article{TanSchreinerHausladenetal., author = {Tan, Jing Jie and Schreiner, Rupert and Hausladen, Matthias and Asgharzade, Ali and Edler, Simon and Bartsch, Julian and Bachmann, Michael and Schels, Andreas and Kwan, Ban-Hoe and Ng, Danny Wee-Kiat and Hum, Yan-Chai}, title = {SiMiC: Context-aware silicon microstructure characterization using attention-based convolutional neural networks for field-emission tip analysis}, series = {Journal of Vacuum Science \& Technology B}, volume = {43}, journal = {Journal of Vacuum Science \& Technology B}, number = {6}, publisher = {AVS}, doi = {10.1116/6.0005068}, abstract = {Accurate characterization of silicon microstructures is essential for advancing microscale fabrication, quality control, and device performance. Traditional analysis using scanning electron microscopy (SEM) often requires labor-intensive, manual evaluation of feature geometry, limiting throughput and reproducibility. In this study, we propose SiMiC: Context-aware Silicon Microstructure Characterization Using Attention-based Convolutional Neural Networks for Field-Emission Tip Analysis. By leveraging deep learning, our approach efficiently extracts morphological features—such as size, shape, and apex curvature—from SEM images, significantly reducing human intervention while improving measurement consistency. A specialized dataset of silicon-based field-emitter tips was developed, and a customized convolutional neural network architecture incorporating attention mechanisms was trained for multiclass microstructure classification and dimensional prediction. Comparative analysis with classical image processing techniques demonstrates that SiMiC achieves high accuracy while maintaining interpretability. The proposed framework establishes a foundation for data-driven microstructure analysis directly linked to field-emission performance, opening avenues for correlating emitter geometry with emission behavior and guiding the design of optimized cold-cathode and SEM electron sources. The related dataset and algorithm repository that could serve as a baseline in this area can be found at https://research.jingjietan.com/?q=SIMIC.}, language = {en} }