An antisite-vacancy pair and a monovacancy were a set of fundamental stable and/or metastable defects in compound semiconductors. Theory predicted that C antisite-vacancy pairs would be much more stable in p-type SiC than silicon vacancies and that they would be a common defect. However, no experimental evidence has yet supported this prediction. Electron-irradiated p-type 4H-SiC was re-examined and the positively charged C antisite-vacancy pairs (CSiVC+) were identified by means of electron paramagnetic resonance and ab initio calculations. These were compared with other co-existing defects such as the C vacancy (VC) and divacancy (VSiVC) and it was shown that CSiVC and VC were very similar, in terms of thermal stability and electronic levels.

Identification of Positively Charged Carbon Antisite-Vacancy Pairs in 4H-SiC. T.Umeda, J.Ishoya, T.Ohshima, N.Morishita, H.Itoh, A.Gali: Physical Review B, 2007, 75[24], 245202 (6pp)