Oxidation of silicon: Is there a slow interface reaction?

Chemical analysis of the surface of an oxidized silicon-germanium mixture by Rutherford backscattering reported recently showed that the silicon is oxidized, but not the germanium. This result provides evidence that the effective oxygen concentration at the silica-silicon interface is low, which is contrary to a slow interface reaction. Strain in the oxide film can result in linear-parabolic oxidation kinetics without a slow interface reaction.