Comparison of defects produced by fast neutrons and 60Co-gammas in high-resistivity silicon detectors using deep-level transient spectroscopy

Measurements of radiation-induced defects in high-resistivity silicon detectors irradiated with 14.1 MeV neutrons and 60Co-gammas have been performed using the Deep-Level Transient Spectroscopy technique (DLTS). Five electron traps and one hole trap were found in both neutron- and gamma-irradiated samples differing only in the relative defect concentrations. Furthermore, two additional levels were only detected in the neutron irradiated detectors. The observed defects are identified by comparing the measured energy levels, capture cross sections, and introduction rates to those known from literature. In addition, these assignments are supported by the annealing behaviour observed in two neutron-irradiated samples during a short-term annealing at room temperature and an isochronal heat treatment. The differences found between the defect production by fast neutrons and 60Co-gammas are discussed.