Accumulation and recovery of disorder on silicon and carbon sublattices in ion-irradiated 6H–SiC

Abstract

Irradiation experiments have been performed at 100, 170 and 300 K for 6H–SiC single crystals using Au 2+ and He + ions over a range of fluences. The evolution of disorder on both the Si and C sublattices has been simultaneously investigated using 0.94 MeV D + Rutherford backscattering spectrometry (RBS) in combination with 12C(d,p) nuclear reaction analysis (NRA) in a 〈0 0 0 1〉 axial channeling geometry. At low doses, a higher rate of C disordering is observed, which is consistent with molecular dynamics simulations that suggest a smaller threshold displacement energy on the C sublattice. At higher doses for He + irradiation, the C disordering appears to increase less rapidly than the Si disordering. Three distinct recovery stages are observed on both the Si and C sublattices in the Au 2+-irradiated 6H–SiC. However, complete recovery of irradiation-induced disorder does not occur during isochronal annealing at temperatures up to 970 K.