Inverse Low Gain Avalanche Detector (iLGAD) Periphery Design for X-Ray Applications

TL;DR

This paper explores the design and optimization of inverse LGAD sensors for X-ray applications, demonstrating their robustness and improved performance after irradiation through TCAD simulations and fabrication.

Contribution

It introduces a new generation of iLGAD sensors optimized for X-ray use, with enhanced radiation hardness and fill factor compared to previous designs.

Findings

First iLGAD generation shows good electrical performance pre- and post-X-ray irradiation.

Second iLGAD generation withstands the same voltage as before irradiation, indicating improved radiation hardness.

Optimized periphery design enhances suitability for X-ray applications.

Abstract

LGAD technology is established within the field of particle physics, as the baseline technology for the timing detectors of both the ATLAS and CMS upgrades at the HL-LHC. Pixelated LGADs have been proposed for the High Granularity Timing Detector (HGTD) and for the Endcap Timing Layer (ETL) of the ATLAS and CMS experiments, respectively. The drawback of segmenting an LGAD is the non-gain area between pixels and the consequent reduction in the fill factor. In this sense, inverse LGAD (iLGAD) technology has been proposed by IMB-CNM to enhance the fill factor and to reach excellent tracking capabilities. In this work, we explore the use of iLGAD sensors for X-Ray applications by developing a new generation of iLGADs. The periphery of the first iLGAD generation is optimized by means of TCAD tools, making them suitable for X-Ray irradiations thanks to the double side optimization. The fabricated iLGAD sensors exhibit good electrical performances before and after an X-Ray irradiation. The second iLGAD generation is able to withstand the same voltage, as contrary to the first iLGAD generation after irradiation.