arXiv subjects

Adam Kozelsky

Publications and source records attributed to Adam Kozelsky.

3 recordsLinked to original sources

arXiv2026

Development of Segmented 4H-SiC LGADs

The wide-bandgap semiconductor 4H-silicon carbide (4H-SiC) offers a compelling combination of radiation hardness, thermal stability, and high critical electric field for particle detection in harsh environments. To compensate for the comparatively low charge generation in SiC, the Low-Gain Avalanche Detector (LGAD) concept can be adopted to provide internal signal amplification. Building on three preceding generations of single-pad 4H-SiC LGAD prototypes fabricated by ion implantation, this work presents the design, fabrication, and initial characterization of segmented 4H-SiC LGAD devices -- the first fabricated and characterized devices reported. Strip detectors with 80~$\mu$m pitch and pixel arrays with 55 and 110~$\mu$m pitch were produced using multiple inter-channel isolation strategies, including geometric separation and oxide-filled trenches. Two-photon absorption transient current technique (TPA-TCT) measurements performed at ELI ERIC demonstrate clear charge separation between adjacent strips with internal gain, confirming functional segmentation.

physics.ins-det↗

arXiv2025

Exploring the Design and Measurements of Next-Generation 4H-SiC LGADs

This contribution presents the design, production, and initial testing of newly developed 4H-SiC Low Gain Avalanche Detectors (LGADs). The evaluation includes performance metrics such as the internal gain layer's efficiency in enhancing signal generation. Initial laboratory and Transient Current Technique (TCT) measurements provide insight into the device's stability and response to the signal. Due to the increase of availability provided by the industry, 4H-SiC is emerging as a strong candidate for the next-generation of semiconductor detectors. Such sensors are promising due to the inherent radiation tolerance of 4H-SiC and its stable operation across a wide temperature range. However, due to the wider-bandgap of 4H-SiC compared to standard silicon, and difficulty to produce high-quality layers thicker than 50 \textmu m, an internal charge multiplication layer needs to be introduced. The presented 4H-SiC LGADs, fabricated by onsemi, are optimized for an N-type substrate and epi wafer. The initial TCT and laboratory test results demonstrate fast charge collection and uniform multiplication across multiple samples produced on a single wafer.

physics.ins-det↗

arXiv2025

First generation 4H-SiC LGAD production and its performance evaluation

This contribution will delve into the design and performance of the newly produced Silicon Carbide Low Gain Avalanche Detectors (4H-SiC LGADs) and provide a comprehensive summary of their measured characteristics. This includes an analysis of the detector's performance, temperature stability, and the effectiveness of the internal gain layer in improving signal generation. The 4H-SiC is re-emerging as a strong candidate for the next generation of semiconductor detectors. This material offers several advantages, including high radiation tolerance and the ability to operate over a wide range of temperatures without significant annealing effects. However, the signals generated by minimum ionizing particles in the 4H-SiC detector are lower compared to the signal produced by standard silicon detectors due to their higher bandgap energy. This is addressed by implementing a charge multiplication layer, which results in the intrinsic gain of the device. The presented 4H-SiC LGADs produced by onsemi are specifically designed and optimized for fabrication on the n-type substrate/epi wafer with the gain layer implanted approximately $1~\mathrm{\mu m}$ below the surface. The first iteration of these LGAD structures was manufactured in early 2024 and since then has been subjected to laboratory evaluation. The measured properties of these detectors align well with the predictions arising from the extensive TCAD simulation studies.

physics.ins-det↗