The formation energy of self-interstitials in C-doped material was deduced from measurements of the optical absorption which was due to H that was bound to isolated self-interstitials. Specimens of C-doped material were sealed into quartz capsules, together with 1atm of H gas at high temperature, and were annealed for 1h before quenching in water. Optical absorption spectra were measured at about 7K. Several peaks coincided with those observed for proton-implanted material. It was concluded that complexes of simple point defects, such as vacancies and self-interstitials, with H atoms were present in the specimens. From the quenching-temperature dependence, of peaks that were identified as being due to H which was bound to self-interstitials, the formation energy of self-interstitials in C-doped samples was estimated to be about 3eV.

Formation Energy of Self-Interstitials in Carbon-Doped Si Determined by Optical Absorption due to Hydrogen Bound to Self-Interstitials N.Fukata, M.Suezawa: Journal of Applied Physics, 1999, 86[4], 1848-53