EARLY STAGES OF OXYGEN-ADSORPTION ON SILICON SURFACES AS SEEN BY ELECTRON-SPECTROSCOPY

The oxidation of silicon surfaces has been studied by AES, XPS and LEED. Attention was focussed on the modifications induced in the AES spectra by oxygen adsorption. It has been shown that the fine structure of the silicon LW transition is changed in the early stages of oxidation. Several steps are found: the first and most stable is a SiOx layer where silicon is probably covalently bonded to oxygen. The second is a silica-like overlayer. The study of the oxygen KLL transition which can be either delocalized or quasi-atomic favors these assignments. © 1979.