Parallel unstructured grid DSMC for the study of molecular gas dynamics in semiconductor manufacturing

Abstract

This paper describes the implementation aspects of a 2D, unstructured grid based Direct Simulation Monte Carlo flow solver for the study of molecular gas dynamics found in thin film deposition processes. A localized data structure base don domain decomposition is developed to improve the particle/molecule tracking, which is otherwise computationally intensive. The method has been implemented on a massively parallel computing platform for shortened simulation time. Results are validated against known analytical solutions and published results. Furthermore, the influence of parameters, such as sticking coefficient and aspect ratio for step coverage on a 1 micrometers wide trench by sputter deposition was studied. The results show that the step coverage deteriorates with increasing sticking coefficient and aspect ratio.