The formation and binding energies, structures and local vibrations of the Oi, O2i, O3i, VO, VO2 and V2O defects were calculated by using a self-consistent total-energy pseudo-potential method. Ionization levels and associated structures were given for VO and V2O, as well as the local vibrational modes for the negative charge states of VO. An Oi frequency at 517/cm was tentatively attributed to an O-induced Si mode of weakly interacting O interstitials. Two competing structures were found for O2i. These were a staggered configuration, and a skewed Oi–Si-Si-Oi configuration, with binding energies of 0.2 and 0.1eV, respectively. Experimental frequencies of O2i at 1060, 1012, 690 and 556/cm were found to originate from the staggered O2i. The frequency of O2i at 1105/cm was found to originate from the skewed configuration above.

Computational Study of Interstitial Oxygen and Vacancy-Oxygen Complexes in Silicon M.Pesola, J.Von Boehm, T.Mattila, R.M.Nieminen: Physical Review B, 1999, 60[16], 11449-63