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.