The properties and formation mechanism of SiC-CSi antisite pairs in 4H-type material were investigated. A high energy barrier had to be overcome for the formation of an antisite pair in the ideal bulk. However, in the presence of other defects, the formation energy and barrier were appreciably lowered. Results were presented concerning the formation energies and diffusion barriers for the formation of an antisite pair next to Si and C vacancies, as well as next to the VC-CSi pair which arose from VSi. The structure and formation energy of the antisite pair were calculated by using ab initio density functional theory in the local density approximation. The results were reproduced satisfactorily by a charge self-consistent density functional theory-based tight-binding method which was used to calculate the diffusion paths and activation energies for formation.

Intrinsic Defect Complexes in α-SiC: the Formation of Antisite Pairs. E.Rauls, Z.Hajnal, A.Gali, P.Deák, T.Frauenheim: Materials Science Forum, 2001, 353-356, 435-8