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

摘要

Irradiation experiments have been performed at 100, 170 and 300 K for 6H-SiC single crystals using Au2+ 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 C-12(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 Au2+-irradiated 6H-SiC. However, complete recovery of irradiation-induced disorder does not occur during isochronal annealing at temperatures up to 970 K. (C) 2001 Elsevier Science B.V. All rights reserved. [References: 30]