Atomistic model structure of the Si(100)-SiO₂ interface from a synthesis of experimental data

We introduce an atomistic model structure of the Si(1 0 0)-SiO2 interface which incorporates atomic-scale information from a variety of experimental probes. The interface model consists of a disordered, topologically perfect oxide network matching the Si substrate without coordination defects. The transition region on the substrate side shows a disordered bonding pattern extending over about two monolayers and including several in-plane Si-Si dimers. On the oxide side, the suboxide matches the amount, the distribution and the location of partially oxidized Si atoms found in photoemission experiments. The mass density profile is in accord with X-ray reflectivity data. Silicon distortions in directions both parallel and perpendicular to the interface show good agreement with ion scattering experiments. (C) 2004 Elsevier B.V. All rights reserved.