Temperature stimulated reverse annealing of neutron induced damage in high resistivity silicon detectors

摘要

Neutron irradiated high resistivity silicon detectors have been subjected to elevated temperature annealings (ETA). It has been found that both detector full depletion voltage and leakage current exhibit reverse annealing behavior for highly irradiated detectors: increase with ETA. Laser induced current shapes have indicated a net increase of acceptor type space charges associated with the full depletion voltage increase after ETA. Data of current deep level transient spectroscopy (I-DLTS) have shown that the dominant microscopic effect is the increase of a level at 0.39 eV. This level is tentatively identified as the V-V(sup (minus)) level at E(sub c)-0.39 eV and/or the C(sub i)-O(sub i) level at E(sub v) + 0.36 eV. Data of thermally stimulated current (TSC) have shown increases of levels at 0.26 eV and 0.40 eV with ETA, suggesting that the level responsible for the reverse annealing effects be the V-V center (V-V(sup (minus)) at E(sub c)-0.25 eV and V-V(sup (minus)) at E(sub c)-0.39 eV). Some local, non-uniform trappings of laser induced electrons and holes have been observed near the pt contact at low voltages after ETA at intermediate temperatures (110--150 (degree)C).