Electron Paramagnetic Resonance Study of Carbon Antisite-Vacancy Pair in p-Type 4H-SiC
Carbon antisite-vacancy pair (CSiVC) is a fundamental defect in SiC, and is theoretically predicted to be very stable in p-type materials. However, this pair was found only in the form of a negatively charged state (i.e., the SI5 center = CSiVC −) in n-type and semi-insulating 4H-SiC, and yet, its presence has not been shown in p-type SiC. In this report, we present the first EPR observation on positively charged CSiVC pairs in p-type 4H-SiC. By carefully examining p-type samples after electron irradiation, we found a pair of new defects with C3v and C1h symmetries. They correspond to “c-axial” pairs (C3v) and “basal” pairs (C1h) of CSiVC +, respectively. The positively charged pairs are characterized by a strong 13C hyperfine interaction due to a dangling bond on a carbon antisite (CSi), which is successfully resolved for the c-axial pairs.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
T. Umeda et al., "Electron Paramagnetic Resonance Study of Carbon Antisite-Vacancy Pair in p-Type 4H-SiC ", Materials Science Forum, Vols. 556-557, pp. 453-456, 2007