Analysis of divacancy related traps induced by proton, neutron and gamma radiation in high resistivity silicon detectors

Defects with deep levels induced in high-resistivity silicon detectors by low and high radiation fluence of protons and neutrons are studied using capacitance and current DLTS. Numerical simulation of I-DLTS and C-DLTS spectra based on the model of charge carrier emission and redistribution of electric field in the detector enabled one to perform the detailed investigation of DLTS spectra. It has been shown that the main DLTS peak in the range of 200 to 260 K may be considered as a result of the interference of deep levels near the midgap – negatively charged divacancy VV− and the Ci–Oi complex. The model describing the broadening of the VV− component of the spectrum, which arises from the divacancy localization inside a cluster, is discussed. The results are compared with those obtained for gamma irradiation, for which the dominant contribution in DLTS spectra arises just from the Ci–Oi complex.