Comparative study of the impact of interpad nominal length on the onset of the charge multiplication in standard segmented LGAD with 2 p-stops and bias ring as isolated structures

Gordana Laštovička-Medin; Jovana Doknic; Ivona Bozovic; Gregor Kramberger; Tomáš Laštovička; Jakob Andreasson; Mateusz Rebarz

doi:10.1016/j.apradiso.2024.111288

Comparative study of the impact of interpad nominal length on the onset of the charge multiplication in standard segmented LGAD with 2 p-stops and bias ring as isolated structures

Appl Radiat Isot. 2024 Jun:208:111288. doi: 10.1016/j.apradiso.2024.111288. Epub 2024 Mar 12.

Authors

Gordana Laštovička-Medin¹, Jovana Doknic², Ivona Bozovic², Gregor Kramberger³, Tomáš Laštovička⁴, Jakob Andreasson⁴, Mateusz Rebarz⁴

Affiliations

¹ Faculty of Natural Sciences and Mathematics, University of Montenegro, Dzordza Vashingtona, 81000, Podgorica, Montenegro. Electronic address: gordana.medin@gmail.com.
² Faculty of Natural Sciences and Mathematics, University of Montenegro, Dzordza Vashingtona, 81000, Podgorica, Montenegro.
³ Jozef Stefan Institute, Jamova cesta 39, 10 000, Ljubljana, Slovenia.
⁴ ELI Beamlines Facility, The Extreme Light Infrastructure ERIC, Za Radnicí 835, 25241, Dolní Břežany, Czech Republic.

PMID: 38518502
DOI: 10.1016/j.apradiso.2024.111288

Abstract

We present an investigation of the interpad region (IP) in the Ultra-Fast Silicon Detector (UFSD) Type 10, utilizing a femtosecond laser and the transient current technique (TCT). We elucidate the isolation structure and measure the IP distance between pads, comparing it to the nominal value provided by the vendor. A comparison of sensors with identical layouts but different nominal IP distances (49 μm vs. 61 μm) and different processing parameters revealed their significant different charge collection properties in the IP.

Keywords: 4D tracking; Bias ring; Fill factor; Interpad layout; Isolation structures; JTE; Segmented LGAD; UFSD; p-stop; pCT.