Time resolved annealing studies of single neutron irradiated avalanche photodiodes

The dark count rate of avalanche photodiodes was used to monitor single neutron created damage and annealing. The experiments achieve a maximum time resolution of 10 ms. Irradiations are carried out at different temperatures between 5/spl deg/C and 25/spl deg/C. Monotonic forward annealing after the neutron interaction was observed with two distinct decay times of 75 ms and 725 ms, respectively. Stepwise forward annealing was observed after this initial period. For some cases reverse stepwise annealing on a time scale up to 30 minutes was detected. The monotonic annealing is discussed in connection with the motion of vacancies in the damage region. The stepwise annealing is suggested to be related to single defect configuration changes.