A Novel Diffusion Coupled Oxidation Model

Abstract

A new approach to the three-dimensional local oxidation of silicon is presented, that is based on a parameter dependent smooth transition zone between silicon and sili­ con dioxide. The resulting two phase problem is solved by calculating a free diffusive oxygen concentration, which reacts with unsaturated silicon to silicon dioxide. This chemical reaction causes a volume dilatation which leads to mechanical stress con­ cerning the surrounding boundary conditions. By a suitable set of parameters this kind of approach is equivalent to the standard sharp interface model based on the fundamental work of Deal and Grove. The main advantage is, that the mesh remains topologically invariant during the progress of oxidation and therefore no remeshing is necessary.