Diffusion-reaction in thermal growth of silicon oxide films on Si

The thermal growth of silicon oxide films on Si in dry O2 is modelled as a dynamical system, assuming that it is basically a diffusion-reaction phenomenon. Relevant findings of the last decade are incorporated, as structure and composition of the oxide/Si interface and O2 transport and reaction at initial stages of growth. The present model departs from the well established Deal and Grove framework (Deal, B.E. and Grove, A. S. General Relationship for the Thermal Oxidation of Silicon, J. Appl. Phys. 36, 3770-3778 (1965)) indicating that its basic assumptions, steady-state regime and reaction between O2 and Si at a sharp oxide/Si interface are only attained asymptotically. Experimental growth kinetics by various authors, obtained for a wide range of growth parameters are shown to collapse into one single curve when the scaling properties of this model equations are explored.