Charge Collection Performance of 4H-SiC LGAD

TL;DR

This paper reports the first fabrication and characterization of a 4H-SiC low gain avalanche detector (LGAD), demonstrating improved electrical performance, gain, and charge collection efficiency suitable for high energy particle physics applications.

Contribution

The study introduces a novel 4H-SiC LGAD (SICAR), optimizing fabrication to significantly reduce leakage current and achieve notable gain and charge collection efficiency.

Findings

Leakage current reduced by four orders of magnitude.

Gain factor of about 2 at 150 V.

Charge collection efficiency of 90% at 100 V.

Abstract

The 4H-SiC material exhibits good detection performance, but there are still many problems like signal distortion and poor signal quality. The 4H-SiC low gain avalanche detector (LGAD) has been fabricated for the first time to solve these problems, which named SICAR (SIlicon CARbide). The results of electrical characteristics and charge collection performance of the 4H-SiC LGAD are reported. The influence of different metal thicknesses on the leakage current of the device is studied.~By optimizing the fabrication process, the leakage current of the detector is reduced by four orders of magnitude. The experimental results confirm this 4H-SiC LGAD has an obvious gain structure, the gain factor of the SICAR is reported to be about 2 at 150 V. The charge collection efficiency (CCE) of the device was analyzed using $\alpha$ particle incidence of 5.54 MeV, and the CCE is 90\% @100~V. This study provides a novel 4H-SiC LGAD radiation detector for application in the field of high energy particle physics.