Ion beam analysis of irradiation effects in 6H-SiC

Irradiation in 6H-SiC single crystal wafers has been performed at temperatures ranging from 150 to 550 K using 2.0 MeV Au²⁺ 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 I¹⁰⁺ ions to ∼0.1 ions/nm². In situ isothermal annealing for 6H-SiC irradiated at 500 K to 2.0 Au²⁺/nm² 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 Au²⁺ irradiation at 500 and 550 K. Complete amorphization at 550 K does not occur up to a maximum fluence of 15 Au²⁺/nm² 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 I¹⁰⁺ irradiation in the He⁺-irradiated specimen near room temperature, remarkable recrystallization at the amorphous-crystalline interfaces around the damage profile is observed.