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

Low temperature annealing of electron irradiation-induced deep levels in $4\mathrm{H}\text{-}\mathrm{SiC}$ is reported. The major deep level transient spectroscopy peak S2 associated with the energy level at $E_c-0.39\mathrm{eV}$ disappears in the temperature range $360–400\mathrm{K}$ , and some rearrangement of the peak S3, associated with the defect $Z_1∕Z_2$ with energy level at $E_c-0.5∕E_c-0.65\mathrm{eV}$ occurs in the temperature interval $400–470\mathrm{K}$ . A net free charge carrier concentration increase goes along with the disappearance of peak S2 at $E_c-0.39\mathrm{eV}$ , 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.