Systematic Analysis of Reliability of Large-Area 4H-SiC Charged Particle Detector under Harsh He Ion Irradiation

Silicon carbide (SiC) detectors have great potential in nuclear fusion diagnosis and intense irradiation field measurement due to their outstanding irradiation resistance, high charge collection efficiency (CCE), and fast pulse response time. However, the irradiation resistance and the performance degradation of SiC detectors as a result of He ion irradiation remains unclear. In this article, SiC detectors based on 4H-type material with the p-i-n junction structure were prepared, and their I-V characteristics, α -particle spectra, and linearity of energy response were evaluated before and after He ion irradiation at fluences ranging from 1 × 1012 to 3 × 1015 cm-2. The preirradiated SiC detector exhibited low dark current (< 1 nA), high CCE (98.5%), and good energy resolution (0.87%). At an He ion irradiation fluence of 1 × 1012 cm-2, detector performance degradation was negligible, with no increase of dark current, CCE decreased to 85%, and a 2.2% degradation of energy resolution. At a fluence of 3 × 1015 cm-2, CCE decreased to 19.3%, with an 8.57% degradation in energy resolution, but the dark current was still lower than 2 nA, with good spectra measurement capabilities and high linearity of energy response. These results indicate that the He ion irradiation resistance of 4H-SiC detectors is 104 times greater than silicon (Si) detectors.