The annealing of P6/P7 centers (VCCSi pairs) in the presence of C vacancies in high concentrations typical for semi-insulating (SI) silicon carbide (SiC) was studied theoretically. The calculated hyperfine parameters support the suggestion of a negatively charged divacancy as the most stable SI-5 center. A possible correlation of the SI-1 and SI-2 spectra with metastable configurations of this divacancy revealed a rather complicated equilibrium of several defect configurations that might be responsible for the large number of electron paramagnetic resonance signals observed in high-purity semi-insulating SiC.

Annealing of Vacancy-Related Defects in Semi-Insulating SiC. U.Gerstmann, E.Rauls, H.Overhof: Physical Review B, 2004, 70[20], 201204 (4pp)