Formation energy of interstitial Si in Au-doped Si

摘要

In this report, we proposed that complexes responsible for optical absorption lines in Si grown in a hydrogen (H) atmsophere were composed of interstitial Si and H atoms and then determined the formation energy of interstitial Si in Au-doped Si from the measurements of optical absorption due to H bound to interstitial Si. In the first experiment, specimens were grown in a hydrogen atmosphere. In the second experiment, Si crystals were doped with Au by a vapor method; namely, specimens were sealed in quartz capsules together wit6h a piece of Au wire and then annealed at high temeprature followed by quenching in water. Then the specimens were doped with H by annealing them in hydrogen atmosphere of 1 atm. followed by quenching. We measured optical absorption of those specimens. From the efect of impurity on the optical absorption spectra of Si grown in a hydrogen atmosphere, we concluded that those optical absorption lines, including 2223 cm~(-1) line, were due to complexes of interstitial Si and H. From the temperature dependence of the intensity of 2223 cm~(-1) line, the formation energy of interstitial Si in Au-doped Si was determined to be about 2.1eV.