Annealing behaviors of vacancy in varied neutron irradiated Czochralski silicon
(1.School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China2.天津市河北工业大学材料科学与工程学院3.School of Information and Communication, Tianjin Polytechnic University, Tianjin 300160, China)
Abstract: The difference of annealing behaviors of vacancy-oxygen complex (VO) in varied dose neutron irradiated Czochralski silicon: (S1 5×1017 n/cm3 and S2 1.07×1019 n/cm3) 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 ℃, divacancies are trapped by interstitial oxygen(Oi) to form V2O (840 cm？1). With the decrease of the 829 cm？1 (VO) three infrared absorption bands at 825 cm？1 (V2O2), 834 cm？1 (V2O3) and 840 cm？1 (V2O) will rise after annealed at temperature range of 200？500 ℃. After annealed at 450？500 ℃ the main absorption bands in S1 sample are 834 cm？1, 825 cm？1 and 889 cm？1 (VO2), 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 Oi 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 VO2 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.
Key words: Czochralski silicon; neutron irradiation; A-center, FTIR