DEEP CENTERS IN UNDOPED SEMIINSULATING INP

Undoped semi-insulating (SI) InP samples, subjected to one-step and mu lti-step wafer annealing, and lightly and normally Fe-doped SI InP sam ples without annealing have been characterized by thermally stimulated current (TSC) spectroscopy. A dominant deep center at 0.63 eV is foun d in all samples and is undoubtedly due to iron. Two prominent TSC tra ps, T-b (0.44 eV) and T-d (0.33 eV), found in undoped SI InP, are thou ght to be related to the phosphorus antisite P-In, and traps at low te mperatures, like T-e (0.19 eV), to the phosphrus vacancy V-P.