A mechanism was proposed for the annealing of vacancy-related defects in SiC, based upon ab initio total energy calculations. The mechanism was based upon the formation and migration of C and N split interstitials resulting in CSi(NC)n or VSi(NC)n complexes as intermediate annealing products: In as-implanted samples, only recombination of nearby defects was possible, e.g., the disappearance of divacancies could be explained by a formation of VSiNC pairs (P12 centers). Dissociation of these very stable pairs below 2000C was not possible. At above 1000C, further aggregation became possible, resulting in electrically and optically inactive VSi(NC)4 complexes. The recombination with C split interstitials, resulting in CSiNC and CSi(NC)2 donors, were discussed as competing processes.

Formation and Annealing of Nitrogen-Related Complexes in SiC. U.Gerstmann, E.Rauls, T.Frauenheim, H.Overhof: Physical Review B, 2003, 67[20], 205202 (8pp)