Improved performance of SiC radiation detector based on metal-insulator-semiconductor structures

摘要

SiC is a typical wide bandgap semiconductor that has demonstrated potential applications in radiation detection and imaging, but its performance must be improved from both a material quality and device design standpoint. In this study, based on a theoretical analysis, we found that it is possible to improve the performance of SiC radiation detectors by changing the device structure from a metal/semiconductor to a metal/insulator/semiconductor design and fabricate and evaluate corresponding devices with a particle radiation detection. We experimentally confirmed that introducing an SiO_2 dielectric layer can effectively improve the energy resolution of detectors, so the effect of the dielectric layer thickness on detectors' performance was further investigated and clarified. We demonstrated that a device with a 100 nm SiO_2 dielectric layer on a 15 μm SiC epitaxial layer achieved the best energy resolution of 0.55% @-40 V under 5.48 MeV alpha particle irradiation. This study provides further insight to accelerate commercial applications of SiC radiation detectors.