Ion beam analysis of irradiation effects in 6H–SiC

Abstract

Irradiation in 6H–SiC single crystal wafers has been performed at temperatures ranging from 150 to 550 K using 2.0 MeV Au 2+ or at 300 K using 50 keV He + ions. Additional irradiation for the He +-irradiated specimen was carried out near room temperature using 50 MeV I 10+ ions to ∼0.1 ions/nm 2. In situ isothermal annealing for 6H–SiC irradiated at 500 K to 2.0 Au 2+/nm 2 was also conducted up to 90 min at the irradiation temperature. The lattice disorder in the irradiated samples has been determined using either 2.0 MeV He + or 0.94 MeV D + channeling analysis along the 〈0 0 0 1〉 axis. Results show that there is a substantial diffusion of the Si defects into a greater depth during the Au 2+ irradiation at 500 and 550 K. Complete amorphization at 550 K does not occur up to a maximum fluence of 15 Au 2+/nm 2 in this study. Significant thermal recovery of the Si defects produced at 150 K was not observed during the subsequent thermal annealing at 500 K. Following the I 10+ irradiation in the He +-irradiated specimen near room temperature, remarkable recrystallization at the amorphous–crystalline interfaces around the damage profile is observed.