Temperature dependences of optical-absorption spectra due to H vibration included in H-point defect complexes and H2* in Si were investigated. Specimens were doped with H by annealing in H2 gas followed by quenching. They were then irradiated with 3MeV electrons at room temperature. Optical-absorption spectra of H-point defect complexes and H2* were measured between 7K and room temperature. The peaks investigated were those at 1838/cm [H2*(AB)], 1870/cm (I2H2), 1987/cm (IH2), 2062/cm [H2*(BC)], 2073/cm (V2H2), and 2122 and 2145/cm (VH2); the complexes in parentheses were responsible for optical-absorption peaks and I, V, AB, and BC denote a self-interstitial, a vacancy, an antibonding site and a bond-centered site, respectively. The temperature-dependent peak positions and linewidths of V-related complexes, H2*(AB) and I2H2 were well explained by the de-phasing relaxation due to an anharmonic coupling of H vibration to one low-frequency mode. On the other hand, the interaction with all phonons in the

relaxation explained those of H2*(AB), H2*(BC), and V2H2. These 2 models were not applicable to IH2.

Temperature Dependence of Vibrational Spectra of H-Point Defect Complexes and H2* in Si. M.Suezawa, N.Fukata, T.Takahashi, M.Saito, H.Yamada-Kaneta: Physical Review B, 2001, 64[8], 085205 (7pp)