Annealing behaviors of vacancy in varied neutron irradiated Czochralski silicon

Abstract

The difference of annealing behaviors of vacancy-oxygen complex (VO) in varied dose neutron irradiated Czochralski silicon: (S1 5×10 17 n/cm 3 and S2 1.07×10 19 n/cm 3) were studied. The results show that the VO is one of the main defects formed in neutron irradiated Czochralski silicon (CZ-Si). In this defect, oxygen atom shares a vacancy, it is bonded to two silicon neighbors. Annealed at 200 °C, divacancies are trapped by interstitial oxygen(O i) to form V 2O (840 cm −1). With the decrease of the 829 cm −1 (VO) three infrared absorption bands at 825 cm −1 (V 2O 2), 834 cm −1 (V 2O 3) and 840 cm −1 (V 2O) will rise after annealed at temperature range of 200–500 °C. After annealed at 450–500 °C the main absorption bands in S1 sample are 834 cm −1, 825 cm −1 and 889 cm −1 (VO 2), in S2 is 825 cm −1. Annealing of A-center in varied neutron irradiated CZ-Si is suggested to consist of two processes. The first is due to trapping of VO by O i in low dose neutron irradiated CZ-Si (S1) and the second is due to capture the wandering vacancy by VO, etc, in high dose neutron irradiated CZ-Si (S2), the VO 2 plays an important role in the annealing of A-center. With the increase of the irradiation dose, the annealing behavior of A-center is changed.