EPR study of carbon vacancy-related defects in electron-irradiated 6H-SiC

The EPR spectra produced in boron-doped 6H-SiC by 2 MeV electron irradiation are described. Three axially symmetric near 77 K spectra Ky1 with g(parallel to1) = 2.0035 and g(perpendicular to1) = 2.0041, Ky2 with g(parallel to2) = 2.0028 and g(perpendicular to2) = 2.0046, Ky3 with g(parallel to3) = 2.0024, g(perpendicular to3) = 2.0048 and with relatively strong hyperfine splittings have been detected. Based on the intensity ratio of HF satellites to the central line these spectra have been assigned to carbon vacancy-related defects. Due to the similarity of HF parameters spectra Ky1 and Ky2 have been tentatively attributed to the same defect in inequivalent crystal sites. The results of preliminary ab initio calculations of carbon vacancy in different charge states are briefly discussed.