Oxidation of Si during the growth of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mi>SiO</mml:mi><mml:mi mathvariant="normal">x</mml:mi></mml:msub></mml:mrow></mml:math>by ion-beam sputter deposition:<i>In situ</i>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 $600\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$. At low temperatures, the variation of incorporated oxygen content is similar to a dissociative adsorption isotherm of ${\mathrm{O}}_{2}$ 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 $\mathrm{SiO}$ 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.