Annealing behavior of vacancies and the Z1/2 levels in n-type 4H-SiC epilayers after 2 MeV electron irradiation has been studied using positron annihilation and deep-level transient spectroscopy. Isochronal annealing studies indicate that silicon vacancy-related defects are primarily responsible for positron trapping. The Z1/2 levels are the predominant deep centers after irradiation and subsequent annealing at 1200 °C. Both the positron-trapping rate at vacancies and the Z1/2 concentration decr... »