Changes in the irradiation defects in high-dose (1.17 x 1019/cm3) neutron-irradiated Czochralski Si at various annealing temperatures were investigated by using the positron annihilation spectroscopy and Fourier transform infra-red spectrometer technique. It was found that divacancies (V2) and V4 abounded in irradiated Czochralski-Si. With increasing annealing temperature, the monovacancy-type defect (such as VO) was annihilated. The results of positron annihilation spectroscopy and Fourier transform infra-red spectrometry showed that the formation of V4 was enhanced when the annealing temperature was 400 to 600C and upon the Fourier transform infra-red spectrometer absorption peak at 829/cm (VO) disappearing, 5 absorption peaks appeared at 825/cm (V2O2), 834/cm V3O2, 840/cm V2O, 720/cm and 919/cm. It was concluded that these defect-impurity complexes prolonged the lifetime of positrons.

Positron Annihilation Spectroscopy Studies of Fast Neutron Irradiated Czochralski Silicon. S.Yang, Y.Li, Q.Ma, H.Liu, Q.Hao, Y.Li, S.Niu, H.Li: Journal of Crystal Growth, 2005, 276[1-2], 43-7