| In this paper, the effect of irradiation doses and annealing conditions on oxygen precipitate and induced defects in fast neutron irradiated nitrogen-doped Czochralski silicon (NCZSi) was studied using Fourier Transform Infrared Absorption Spectrometer (FTIR) and Optical microscope. In addition, the effect of nitrogen atmosphere annealing on fast neutron irradiated Czochralski silicon (CZSi) was investigated.Oxygen precipitates were formed in NCZSi when annealed at high temperature. Spherical oxygen precipitates, α -SiO2, lamellar oxygen precipitates and N-O complexes were found using low temperature FTIR. Stacking faults, dislocations and dislocation loops appeared after etching. With increasing annealing time, the density of defects increases.Rapid thermal process (RTP) was used in the intrinsic gettering (IG) process of fast neutron irradiated CZSi. The effect of RTP conditions on bulk stacking faults (BSFs) and denuded zone (DZ) was investigated. RTP didn't change the process of oxygen precipitation. Oxygen precipitation behavior of the irradiated nitrogen-doped samples was different from that of the non-irradiated samples for the vacancy type defects induced by fast neutron irradiation, and different from that of the irradiated samples for the promotion effect of nitrogen on the oxygen diffusion. With increasing RTP temperature and decreasing cooling rate, DZ width increased.Fast-neutron irradiated CZ-Si anneal in nitrogen atmosphere, compared with anneal in argon atmosphere, interstitial oxygen concentration decreased more. N-0 complexes and lamellar oxygen precipitates were found using low temperature FTIR. Beside those, two new absorption peaks located at 2850 and 2920cm-1 were found which intensity increased with the increase of nitrogen and oxygen concentration. Some nitrogen atoms diffuse into silicon when CZSi anneal in nitrogen atmosphere and then change the behavior of oxygen precipitation. |
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