Hydrogen-related complexes formed by electron-irradiation of hydrogenated silicon - art. no. 035203

We studied point defects, vacancies (V), and self-interstitials (I), formed by room-temperature electron irradiation of hydrogenated Si via the observ ation of the optical-absorption spectra due to complexes formed of hydrogen and paint defects. The formation of H-2*, a metastable state of H-2 in Si, was also studied. Specimens were n-type, p-type, and high-purity Si crysta ls. They were doped with hydrogen (H) by annealing at 1300 degreesC in H-2 gas followed by quenching. Then they were irradiated with 3 MV electrons at room temperature. We measured their optical-absorption spectra by a Fourie r-transform infrared spectrometer at about 7 K. Many optical-absorption pea ks were observed. Among them, 1987 and 1990 cm(-1) peaks were weak in B-dop ed specimens and the 2122 cm(-1) peak was weak in P-doped specimens. These results support the hypothesis that the 1987 and 1990 cm(-1) peaks and the 7122 cm(-1) peak are due to complexes including I and V, respectively. The H-2* concentration does not show good correlations with the concentrations of V and I. We hypothesize that H-2* is formed from the interaction between an H-2 and a Frenkel pair.