The interaction of H with radiation-induced defects in Czochralski-grown crystals was studied by means of infra-red absorption spectroscopy and ab initio modelling. The H and/or D was introduced into the crystals by in-diffusion from H2 or D2 gas at 1200 to 1300C. The samples were then irradiated with fast electrons (2 to 4MeV) and annealed at 100 to 600C. The centers (A-center, Ci-Oi complex, divacancy) which were produced by the irradiation were the same in both untreated and treated samples. Heat treatment of the H-treated samples resulted in an increased loss of these centers and in the formation of centers which contained H. The disappearance of A centers at 100 to 150C was related to the appearance of 3 local vibrational modes; at 943.5, 2126.4 and 2151.5/cm. The isotopic shifts of these lines were deduced from measurements on samples which were doped with both H and D. The lines were identified as being related to the stretching vibrational modes of a complex that consisted of one O, and two H, atoms sharing a vacancy site (V-O-H2 complex).

Observation and Theory of the V-O-H2 Complex in Silicon V.P.Markevich, L.I.Murin, M.Suezawa, J.L.Lindström, J.Coutinho, R.Jones, P.R.Briddon, S.Oberg: Physical Review B, 2000, 61[19], 12964-9