Positron study of electron irradiation-induced vacancy defects in SiC

Based on positron annihilation experiments, we have proposed that in 3C-SiC isolated silicon vacancies are responsible for positron trapping after electron irradiation. We have also proposed that in hexagonal SiC one type of vacancy defects survives after annealing at 1000 degrees C which is attributable to carbon-vacancy-carbon-antisite complexes or silicon-vacancy-nitrogen pairs, while carbon vacancies, silicon vacancies and divacancies are excluded. In this study, from the theoretical calculations of positron lifetime and Doppler broadening of annihilation radiation, the above proposals are confirmed. (c) 2005 Elsevier B.V. All rights reserved.