Investigation of the Si Oxidation Process by XANES Spectroscopy Using Synchrotron Radiation

Abstract
Initial oxidation of Si(100) and Si(111) surfaces has been investigated by XANES (X-ray absorption near-edge structure) spectroscopy using synchrotron radiation. At room temperature, oxidation of Si(111) surfaces proceeds much faster than that for Si(100) surfaces. The XANES spectra indicate that oxygen is atomically adsorbed onto the Si surfaces in initial stages of oxidation at room temperature. As oxidation on the surface proceeds, the XANES spectra exhibit the formation of a continuum shape resonance. The local electronic states and the local site structure for the progressive oxidation process are discussed.