Investigation of two infrared bands at 1032 and 1043 cm(-1) in neutron irradiated silicon

We report on infrared (IR) studies of defects in Czochralski-grown silicon (Cz-Si) subjected to fast neutron irradiation and subsequent thermal anneal s. We focus mainly on the investigation of the VO4 defect which, in the lit erature, has been correlated with the pair of bands (1032 and 1043 cm(-1)) in neutron-irradiated Si and another pair of bands (983 and 1004 cm(-1)) in oxygen-implanted Si. Semiempirical calculations of the localized vibration al mode frequencies of the VO4 structure support its correlation with the s econd pair of bands. This correlation is consistent with the ascertainment that the zero point energy of each VOn (n=1,2,3,4) defect is smaller than t he zero point energy of the constituent defects VOn-1, O-i, that is: E-VOn< EVOn-1+E-Oi. (C) 2001 American Institute of Physics.