A theoretical study of two novel SiC and GaN ultraviolet avalanche drift detectors with front-illumination

Abstract

Two novel SiC and GaN Ultraviolet avalanche drift detector (ADD) concepts have been investigated in this manuscript. One is a combination of a APD collecting and multi drift ring structure (MDR-ADD), the other is a detector structure with an APD collecting and a field plate drift configuration (FPD-ADD). The feasibility of the device operation is verified by the TCAD simulation. The APD can be operated in either Geiger mode or linear mode. In the former case, the detector is appropriate for a single photon avalanche detector with the large collection area. In the latter case, the device is well suited to be a low noise scintillation detector with more flexibility. Those novel structures will remain the high avalanche gain with small high electronic field while keep big light absorption area. This could help enlarge the tolerance to the SiC or GaN wafer quality, which is a key restriction to the wide bandgap semiconductor Solid-State Ultraviolet Devices. Those novel ADD concepts are supposed to have better performances in detecting ultraviolet light with low dark current, better noise suppression and high gain.