THERMALLY STIMULATED AND LEAKAGE CURRENT ANALYSIS OF NEUTRON-IRRADIATED SILICON DETECTORS

Thermally stimulated current measurement of neutron irradiated silicon detectors have been performed. Several energy levels have been observed, revealing in particular the presence of the vacancy-oxygen complex (A center) in its double configuration, the divacancy in single (V2-) and double (V2--) minus charge state and the vacancy-phosphorous complex (E center). The increase of the leakage current of the irradiated diodes seems to be caused mainly by the presence of the E and V2- defects. The E centers give the main contribution to this effect, nearly 25 times higher than the V2- one, while the current terms related to the other defects are almost irrelevant in the generation of the total leakage current of the device. A general agreement with leakage current constant measurements and annealing behaviours has been observed.