The performance of 4H–SiC detector at high temperature after gamma irradiation

Abstract

A 4H–SiC detector based on the Schottky diode was fabricated and the combined influence of high temperature and gamma irradiation on 4H–SiC detector has been investigated. We tested the detector's performance at high temperature before gamma irradiation. I–V characteristics and the alpha energy spectra were measured with the 4H–SiC detector before gamma irradiation at high temperature up to 200 °C. The leakage current of the 4H–SiC detector was only 98.7 nA at 200 °C and with a operating voltage of 70 V. The detector showed an energy resolution of 2.36% at 200 °C in detection of 241Am alpha-particles. Then the detector was irradiated by 60Co gamma-ray up to a dose of 1 MGy. I–V characteristics measurements and α energy spectrum measurements were also performed at 200 °C after each irradiation. Both the forward current and the reverse current increased after gamma irradiation. The Schottky barrier height was extracted from the forward I–V curves and it decreased by 0.17 V at a dose of 1 MGy. The response for 241Am source showed that the charge collection efficiency of the detector reduced by only 1.6% and the FWHM can be regarded as unchanged. It has been proved that 4H–SiC detector can work well at 200 °C after exposure to 60Co gamma-ray of 1 MGy.