Electrical Properties and Gain Performance of 4H-SiC LGAD (SICAR)

The 4H-SiC material exhibits good detection performance, but there are still many problems like signal distortion and poor signal quality compared with silicon. The 4H-SiC low-gain avalanche detector (LGAD) device can effectively improve the signal-to-noise ratio and signal quality due to the presence of internal amplification. A 4H-SiC low-gain avalanche detector has been fabricated and named SIlicon CARbide (SICAR). 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. Experimental results confirm that this 4H-SiC LGAD exhibits a distinct gain structure. The gain factor was analyzed using $\alpha $ particle incidence of 5.54 MeV, and the gain factor is about 3@350 V. This study provides a novel 4H-SiC LGAD radiation detector for applications in the field of high-energy particle physics.