Metastable Defects in Low-Energy Electron Irradiated n-Type 4H-SiC
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.
Anton J. Bauer, Peter Friedrichs, Michael Krieger, Gerhard Pensl, Roland Rupp and Thomas Seyller
F. C. Beyer et al., "Metastable Defects in Low-Energy Electron Irradiated n-Type 4H-SiC", Materials Science Forum, Vols. 645-648, pp. 435-438, 2010