It was recalled that there existed a large amount of published data concerning the effects of high-energy electron irradiation upon the formation of deep trapping levels in this material. Most of these data were for bulk material or for material which had been grown by vapor phase epitaxy. However, it was unclear whether these studies were representative of organometallic vapor-phase epitaxial material or of molecular beam epitaxial material. The present results exhibited appreciable differences in the behavior of materials which had been produced by using these techniques. Deep-level transient spectroscopy was used here in order to characterize the deep electron traps which were formed during 7MeV electron irradiation. It was found that an additional trapping level was produced in organometallic vapor-phase epitaxial material with a high background doping level, and that carrier removal from this material was not a simple function of increased electron fluence.

G.H.Yousefi, J.B.Webb, R.Rousina, S.M.Khanna: Journal of Electronic Materials, 1995, 24[1], 15-20