The optical absorption spectra of 2 types of electron-irradiated H-doped material were studied in order to determine the species of point defects which were included in H plus point-defect complexes. The specimens were C-doped (1.7 x 1017/cm3) or high-purity (4 x 1012/cm3). They were doped with H by annealing in H2 gas and quenching. They were then irradiated with 3MV electrons at room temperature. The optical absorption spectra were measured by using a Fourier-transform infra-red absorption spectrometer at about 6K. The intensities of the 1987 and 1990/cm peaks in C-doped specimens were markedly weaker than those of the high-purity specimens. This supported the suggestion that the 1987 and l990/cm peaks were due to a self-interstitial plus two H-atom complex, and not due to a vacancy plus two H-atom complex; since the self-interstitial was known to kick out substitutional C to give interstitial C. This resulted in a decrease in self-interstitial concentration in C-doped material.

Hydrogen-Point Defect Complexes in Electron-Irradiated C-Doped and High-Purity Si M.Suezawa: Japanese Journal of Applied Physics - 2, 1999, 38[6A/B], L608-10