A Simulation System for Diffusive Oxidation of Silicon: One-Dimensional Analysis

Thermal oxidation of silicon is described as a three-component thermodynamic local process involving silicon, silicon oxide, and oxygen molecules. A simplified system of model equations is used to demonstrate the evoluton of the Si ―SiO₂interface. For the one-dimensional case the equivalence with the model of Deal and Grove could be shown analytically. For that purpose effective interface coordinates have been introduced which establish the connection between the conventional concept of sharp interfaces and our “diffusive” interface, i.e., a transition region between pure silicon and pure silicon oxide.