X-RAY PHOTOELECTRON SPECTROSCOPIC CHARACTERIZATION OF ULTRA-THIN SILICON-OXIDE FILMS ON A MO(100) SURFACE

Ultra-thin films of silicon oxides supported on a Mo(100) surface have been studied using X-ray photoelectron spectroscopy (XPS). The films were synthesized by evaporating Si onto the Mo surface in oxygen ambient and were subsequently characterized using XPS with respect to the chemical states of silicon and the composition of the film. It has been found that the silicon oxide, prepared at room temperature with a silicon deposition rate of approximately 1.2 angstrom/min and an oxygen pressure of 2 x 10(-5) Torr, consisted of predominantly silicon dioxide with a small fraction of suboxides. Annealing to approximately 1300 K yielded a stoichiometric film of SiO2. The suboxides are believed to further react with oxygen forming SiO2 at an elevated temperature.