GROWTH-KINETICS OF THERMAL SIO2 THIN-FILMS

This work presents a simple model for the thermal growth of SiO2 thin films on silicon substrates which may shed some light on the theory of silicon oxidation processes. In the model it is assumed that the time rate evolution of the oxidized region is proportional to the average number of non-oxidized silicon sites in a transition region. As a cons equence, the oxide thickness x is found to scale with the oxidation ti me as x similar to tb in agreement with a large number of experimental data. The value of the exponent b is found to be in the range of 1/2 less than or equal to b less than or equal to 3/2 depending on the oxi dation region. The model agrees with the Deal and Grove linear-parabol ic law with no 'anomalous region' in the time dependence for short oxi dation times. Furthermore, a supralinear regime is predicted in the ea rly stages of the oxidation process.