Oxidation of Si during the growth of SiOx by ion-beam sputter deposition: In situ x-ray photoelectron spectroscopy as a function of oxygen partial pressure and deposition temperature

Abstract

Oxidation of silicon during the growth of silicon oxide by ion beam sputter deposition was studied by in situ x-ray photoelectron spectroscopy as a function of oxygen partial pressure at various deposition temperatures below 600 degrees C. At low temperatures, the variation of incorporated oxygen content is similar to a dissociative adsorption isotherm of O-2 on Si indicating that the surface-confined reaction of the deposited Si atoms with the adsorbed oxygen atoms is the main process. However, it shows a three-step variation with the oxygen partial pressure at high temperatures. The evolution of SiO species confirmed by the XPS indicates that an adsorption-induced surface reaction and a diffusion-induced internal reaction are the main pathways for the Si oxidation.