A new model for low pressure chemical vapor deposition of SiO2 films by ozone augmented tetraethoxysilane

A simple model has been developed to analyze the low pressure chemical vapor deposition (LPCVD) of SiO₂ films from tetraethoxysilane (TEOS) and ozone. It is found that the model correlates well the experimental data taken at 30 to 90 Torr which is the range of the Applied Materials 5000 reactor. The model shows from correlations of experimental data that gas phase reaction reduces the deposition rate and that this effect becomes more significant at temperatures above about 365°C. The model also explains successfully the trend in experimental data on Arrhenius plots for pressures from 30 to 90 Torr. These data indicate that the temperature, T_m, at which the deposition rate is a maximum, decreases as the pressure is increased. This occurs because the effect of parasitic gas phase reactions becomes more important at higher pressure. Furthermore, thetrends predicted buy our model are consistent with the experimental data taken under atmospheric pressure chemical vapor deposition (APCVD), even though these conditions are outside the range of applicability of this model which assumes low pressure and therefore very high rates of diffusion.