Interaction of oxygen with evaporated silicon films. An infrared study

Abstract

Spectra due to adsorbed oxygen species have been observed between 1200 and 600 cm^–1. A pair of bands, at 970 and 730 cm^–1, which appear after exposure of silicon to oxygen at ≈ 2 × 10^–5 Pa min have been identified tentatively as a peroxide-like surface species. A second pair at 860 and 750 cm^–1, which appear at exposures > 100 Pa min, are identified with a surface Si—O—Si group gradually replacing the peroxide-like monolayer species. Similarity in the logarithmic growth of the bulk oxide on silicon and the development of bands at 1130 and 1030 cm^–1 allow the identification of interstitial oxygen.