Studies of deep levels in high resistivity silicon detectors irradiated by high fluence fast neutrons using a thermally stimulated current spectrometer

Measurements of deep level spectrum of high resistivity silicon detectors irradiated by high fluence fast neutrons (Φn: 2 x 1012n/cm2) have been made using a thermally stimulated current (TSC) spectrometer. It has been found that at least nine new defect levels, with peaking temperature of 19K, 27K, 36K, 44K, 49K, 83K, 93K, 105K, and 120K, begin to appear when Φn ≥ 1 x 1013n/cm. All peaks have strong dependences on the filling voltage (Vfill, forward bias) or injection current especially for high fluence (Φn ≥ 1013 n/cm2) situations. The defect concentration, energy level in the band gap, and cross section of each deep level, totaling, at least 13, have been studied systematically and possible identifications of the levels have been discussed