Results on defects induced by 60Co gamma irradiation in standard and oxygen-enriched silicon

Radiation-induced defects in silicon diodes were investigated after exposure to high doses of 60Co gamma irradiation, using Deep Level Transient Fourier Spectroscopy and Thermally Stimulated Current methods. The main focus was on differences between standard and oxygen-enriched material and the impact of the observed defect generation on the diode properties. Two close to mid gap trapping levels and a bi-stable donor level have been found to be responsible for the main macroscopic changes both in standard and oxygen-enriched float zone diodes.