Annealing behavior of the carbon vacancy in electron-irradiated 4H-SiC

Electron paramagnetic resonance (EPR) was used to study the annealing behavior of the positively charged carbon vacancy (EI5 center) in electron-irradiated 4H-SiC. At ∼1000°C the EPR signal of the defect starts decreasing gradually. Clear ligand hyperfine structure is still observed after annealing at 1350°C, while the central line can be detected after a 1600°C anneal. A similar annealing behavior was also observed for the EI6 center suggesting that this defect may be also the positively charged carbon vacancy but at the hexagonal lattice site.