화학공학소재연구정보센터
Materials Science Forum, Vol.475-479, 1341-1344, 2005
Studies of damage accumulation in 4H silicon carbide by ion-channeling techniques
Single crystal 4H-SiC was irradiated with 2 MeV Au ions at 165 K. Ion-induced defect configurations and damage accumulation were studied by ion-channeling techniques along the < 0001 >, < 4403 > and < 2201 > directions. A nonlinear dependence of damage accumulation is observed for both the Si and C sublattices along all three directions, and the relative disorder observed along the < 4403 > and < 2201 > directions is much higher than that along the < 0001 > direction. The damage accumulation can be described by a disorder accumulation model, which indicates that defect-stimulated amorphization is the primary amorphization mechanism in SiC, and the high disorder level for the large off-axis angles is attributed to particular defect configurations. Molecular dynamics (MD) simulations demonstrate that most single interstitial configurations are shielded by Si and C atoms on the lattice sites along the < 0001 > direction, which significantly reduces their contribution to the backscattering/reaction yield along the < 0001 > direction.