A steady laminar flow coupled with heat transfer, gas-phase chemistry, and surface chemistry model, was numerically solved for optimization of thermal chemical vapor deposition (CVD) from a gas mixture of silane and helium in the axis-symmetrical rotating/stagnating reactor with and without a rotational showerhead. At first, through computational fluid dynamics (CFD), the rate of deposited silicon on substrate was calculated and validated with the benchmark solutions from the literature. The computational model was then integrated with the dynamic model of Taguchi method to optimize the process parameters formulating a correlation to minimize thickness deviation of deposited silicon film oil the substrate in the different sizes. In particular, the result shows thickness deviation of deposited silicon film can be reduced to 5.8% and 11% from 18% and 36% over a wafer in the diameters of 0.15 m and 0.3 m, respectively, in the thermal CVD process with the optimal conditions ill this work. (C) 2007 Published by Elsevier B.V.