Optical characterization of native defects in 4H-SiC irradiated by 10 MeV electrons with subsequent annealing

Abstract

Low-temperature photoluminescence was employed to investigate the defects of 4H-SiC crystals after high-energy electron irradiation, and the annealing characteristics and dependence of the detecting temperature and irradiation doses were investigated. Results showed that the emission, associated with carbon antisite-vacancy (V_CC_Si)⁺ defects was dominant in the electron-irradiated 4H-SiC crystal. With increase in detecting temperature, the emission decreased demonstrating red-shifted, and the full width at halfmaximum broadened, which was attributed to the increase in the concentration of carriers arising from thermal activation at high temperature. The emission intensity was the highest value at an irradiation dose of 7.9×10¹⁸ e/cm², and then began to decrease. This revealed the lattice damage caused by long-term high-energy irradiation, which reduced the intensity of the defect radiation in the spectrum.