A new model for generation-recombination in silicon depletion regions after neutron irradiation

Abstract

Deep level transient spectroscopy has been used to investigate defects in high resistivity silicon diodes after neutron irradiation. Three defects have been correlated with the leakage current. The leakage current in the diodes is found to be a factor of 50 to 600 greater than expected from standard Shockley-Read-Hall (SRH) theory for the observed defect-concentrations. The results can be explained by an enhancement factor due to intercentre transfer of charge between defects in close proximity to each other. It is proposed that a possible mechanism for this process is rapid, direct transfer between a deep donor state and a deep acceptor state. An unidentified defect is observed at E/sub C/-0.45/spl plusmn/0.02 eV which anneals at /spl sim/700/spl deg/C. This defect is correlated to excess leakage current in both diodes and charge coupled devices.