Control of carbon vacancy in SiC toward ultrahigh-voltage power devices

Abstract A carbon vacancy defect is one of the most abundant point defects in SiC (as-grown, irradiated, annealed) and of technological importance because the acceptor-like level of a carbon monovacancy (Z 1/2 center: E C – 0.63 eV) works as the primary carrier-lifetime killer in 4H–SiC. The carbon vacancy defects can be preferentially generated by either low-energy electron irradiation or high-temperature treatment in an inert gas ambient. On the other hand, the carbon vacancy defects can be almost eliminated by either a carbon-ion implantation process or thermal oxidation. By combination of these techniques, the density of carbon vacancy defects can be controlled in the wide range from 10 11  cm −3 to 10 15  cm −3 or even higher.