Short-Term Annealing in Electron-Irradiated p-Type Silicon

Studies of short-term annealing of minority carrier lifetime in bulk p-type silicon following ~1.4 MeV pulsed electron irradiation are reported. Investigations were performed on vacuum-float-zone boron-doped material in the temperature range 235-3860K and the maximum fluence employed was ~5 x 1012 electrons/cm . Simple exponential recovery under isothermal conditions, a characteristic of first order reaction kinetics, was observed. The amount of unstable damage varied as exp (-t/?R), where ?R is the characteristic recovery time. The temperature dependence of ?R yielded an activation energy of 0. 32 ± 0. 03 eV for the recovery process. The current results, when extrapolated to lower temperatures, compare quite closely with Watkins' EPR data for similar material. It is concluded that the present data is consistent with the observation of neutral vacancy annealing.