The VO defect was one of the major defects produced by irradiation in Cz-grown Si. Its presence in the infrared spectra was manifested by a localized vibration mode band at 829/cm. Upon annealing, the decay of this band was accompanied by the emergence in the spectra of another localized vibration mode band at 890/cm generally attributed to the VO2 defect. The annealing of the VO center was treated in the literature by considering mainly two reaction processes in neutron irradiated material, that is, VO + SiI → Oi and VO + Oi → VO2, which could occur in parallel. There were some points, however, which cannot be explained within the above reaction scheme. Infra-red, X-ray, transmission
electron microscopic and selective etching investigations were made of the annealing behavior of the VO defect in neutron-irradiated Cz-grown Si samples which were subjected to various high-temperature high-pressure treatments prior to the irradiation. The contribution of each of the above two reactions to the whole annealing process of the VO defect and its conversion to the VO2 defect was studied. The results were analyzed by taking into account that the state of the self-interstitials, adjacent to the O precipitates and the structural defects formed due to the high-temperature high-pressure treatment, was different for each sample because of the different treatments.

Study of the Conversion of the VO to the VO2 Defect in Silicon Heat-Treated under Uniform Stress Conditions. C.A.Londos, I.V.Antonova, M.Potsidou, A.Misiuk, J.Bak-Misiuk, A.K.Gutakovskii: Journal of Applied Physics, 2002, 91[3], 1198-203