Numerical modeling of silicon film deposition in very-high-frequency plasma reactor

We present a numerical modeling of plasma-enhanced chemical vapor deposition (PECVD) of silicon film from SiH₄ and H₂ gas mixtures in very-high-frequency (VHF) plasma reactor. The model is composed by electron impact, gas-phase, and surface reactions in a well-mixed reactor model. A set of plasma parameters such as electron density, electron temperature and electron impact reaction rates is determined separately by nonequilibrium plasma model and used as inputs for well-mixed reactor models. The gas-phase reactions include electron impact and neutral-neutral reactions. Some of unknown rates of surface reactions are determined using quantum chemical calculations and transition state theory. In well-mixed reactor models, concentrations of each chemical species are calculated in a steady state condition using mass conservation equation uniformed through the reactor. Numerical results of growth rate as a function of plasma reactor operating parameters show good agreement with experimental ones. Finally optimal operating parameters are investigated using our model combined with design of experiments and optimization techniques.