Deep-level defects in irradiated epitaxial layers of 4H-type material which had been grown by chemical vapor deposition were studied by using deep-level transient spectroscopy. Measurements which were made of irradiated p+n junctions, at temperatures ranging from 100 to 750K, revealed the presence of several electron traps and one hole trap, with thermal ionization energies that ranged from 0.35 to 1.65eV. Most of these defects could already be detected after irradiation doses which were as small as 5 x 1013/cm2. The capture cross-sections of 2 of the defects were shown to be temperature-independent.

C.Hemmingsson, N.T.Son, O.Kordina, J.P.Bergman, E.Janzén, J.L.Lindström, S.Savage, N.Nordell: Journal of Applied Physics, 1997, 81[9], 6155-9