Multiscale analysis of nonequilibrium rarefied gas flows with the application to silicon thin film process employing supersonic jet

Abstract

The new method for the analysis of rarefied gas flows is introduced in this paper. This method is based on the multiscale analysis that connects the thermofluid phenomena as different time and spatial scales by constructing the reasonable physical models among them. First, an intermolecular potential model is constructed from the ab initio molecular orbital calculations. Next, the collision models such as the collision cross section and the scattering angle are constructed by the statistical analysis of the classical trajectory calculations with the new intermolecular potential model. Finally, these collision models are applied with the direct simulation Monte Carlo calculation. In this way, this multiscale modeling does not require any empirical parameters except the electron wave functions and this method is widely applicable to the various rarefied gas flows. As a practical example, the interaction of SiH4 and H2 gas, which is widely used in the semiconductor manufacturing process, is considered.