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

Annealing Behavior of the Carbon Vacancy in Electron-Irradiated 4H-SiC. Z.Zolnai, N.T.Son, C.Hallin, E.Janzén: Journal of Applied Physics, 2004, 96[4], 2406-8