Ion irradiation induced bubble relaxation in SiC

Abstract

He ion irradiation at 140 keV and subsequent annealing at 1200 K were used to introduce voids in 4H-SiC. Then, 1 MeV Si ion irradiation at room temperature was used to study irradiation-induced athermal annealing. Transmission electron microscopy and channeling Rutherford backscattering spectrum analysis were used to characterize samples. Platelet-like voids were formed at the boundary of heavily damaged layer with Si ions implanted to a fluence of 1×1015 cm−2. When Si fluence was increased to 1×1016 cm−2, transition of platelet-like voids into large voids was observed. The study provides evidence of ion irradiation induced athermal annealing. Monte Carlo simulation of atomic displacement on the internal surface of the He bubble suggests that ballistic collision from damage cascades plays an important role in bubble relaxation.