Low temperature annealing of electron irradiation induced defects in 4H-SiC

Low temperature annealing of electron irradiation-induced deep levels in 4H-SiC is reported. The major deep level transient spectroscopy peak S2 associated with the energy level at E_c-0.39 eV disappears in the temperature range 360–400 K, and some rearrangement of the peak S3, associated with the defect Z₁/Z₂ with energy level at E_c-0.5/E_c-0.65 eV occurs in the temperature interval 400–470 K. A net free charge carrier concentration increase goes along with the disappearance of peak S2 at E_c-0.39 eV, whereas the charge collection efficiency of the diode does not experience any significant change. An interpretation of the annealing of peak S2 on a microscopic scale is given.