Annealing of vacancy-related defects in semi-insulating SiC

Abstract

The annealing of $P6∕P7$ centers (${\mathrm{V}}_{\mathrm{C}}{\mathrm{C}}_{\mathrm{Si}}$ pairs) in the presence of carbon vacancies in high concentrations typical for semi-insulating (SI) silicon carbide (SiC) is 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 reveals 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.