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

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 alpha particle radiation detection. We experimentally confirmed that introducing an SiO2 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 SiO2 dielectric layer on a 15 mu m 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.