Metastable Defects in Low-Energy Electron Irradiated <i>n</i>-Type 4H-SiC

Abstract

After low-energy electron irradiation of epitaxial n-type 4H-SiC, the DLTS peak amplitudes of the defects Z1/2 and EH6/7, which were already observed in as-grown layers, increased and the commonly found peaks EH1 and EH3 appeared. The bistable M-center, previously seen in high-energy proton implanted 4H-SiC, was detected. New bistable defects, the EB-centers, evolved after annealing out of the M-center, EH1 and EH3. The reconfiguration energies for one of the two EB-centers were determined to be about 0.96 eV for both transitions: from configuration I to II and from configuration II to I. Since low-energy electron irradiation (<220 keV) affects mainly the carbon atom in SiC, both the M- and EB-centers are likely to be carbon related defects.