The initial oxidation of silicon: new ion scattering results in the ultra-thin regime

We present new results on the SiO2Si system obtained by high resolution medium energy ion scattering. Isotopic labeling experiments demonstrate that the traditional Deal Grove and related models fail for sub-10 nm films. Any realistic model in this ultra-thin film region should include near-interfacial and surface exchange reactions. We also observed that the surface can be roughened during oxidation. Simple models explaining the genesis of roughness during active oxidation and in a transition regime between active and passive oxidation are given, based on relative rates of various surface processes.