Infra-red studies of oxygen adsorbed on evaporated germanium films

Abstract

The spectra of four infra-red active species between 550 and 4000 cm^–1 have been observed. A band which appears after exposure of germanium to oxygen for up to 10^–6 Torr min has been identified tentatively as the O^–₂ ion adsorbed over bare germanium, a second pair of bands at 690 and 780 cm^–1 after exposures between 10^–6 and 10^–1 Torr min are identified with a surface Ge—O—Ge group. Similarty in the logarithmic growth of the bulk oxide on germanium and the development of a band at 840 cm^–1 allow identification of interstitial oxygen, and a band at 750 cm^–1 confirms the existence of Ge—O^– in the surface during the growth of the bulk oxide layer as postulated by Bennett and Tompkins.