The properties of irradiation-induced point defects, and thermal equilibrium vacancies, were studied by detecting H interaction with the point defects. Firstly, the irradiation temperature dependence of the point defect concentration was shown. A study was made of the optical absorption spectra of complexes, of H and point defects, as generated by the electron irradiation of hydrogenated crystals at low temperatures. The concentrations of complexes of H, with vacancy and Frenkel pairs, revealed a non-monotonic dependence upon irradiation temperature. Thus, a metastable interstitial–vacancy (Frenkel pair) model was not applicable to electron-irradiated Si. From the dependences of the intensity ratios of the optical absorption due to complexes of H2 with point defects, the migration energies of self-interstitial and Frenkel pairs, relative to that of the vacancy, were determined. The energies were found to be similar. Secondly, the vacancy formation energy in high-purity Si was determined by using a new quenching method. That is, specimens were heated in H2 gas at various temperatures, and quenched in water. The formation energy which was determined by using the above method was 4.0eV. This agreed well with theoretical values.

Point Defects in Silicon Crystals Studied via Complexes with Hydrogen. M.Suezawa, N.Fukata, Y.Takada, R.Taniguchi, F.Hori, R.Oshima: Microelectronic Engineering, 2003, 66[1-4], 258-67