Transient chemical vapor deposition simulations

The numerical modeling of laminar reacting gas flows in thermal Chemical Vapor Deposition (CVD) processes commonly involves the solution of convection-diffusionreaction equations for a large number of reactants and intermediate species. These equations are stiffly coupled through the reaction terms, which typically include dozens of finite rate elementary reaction steps with largely varying rate constants. The solution of such stiff sets of equations is difficult, especially when time-accurate transient solutions are required. In this study various numerical schemes for multidimensional transient simulations of laminar reacting gas flows with homogeneous and heterogeneous chemical reactions are compared in terms of efficiency, accuracy and robustness. As a test case, we study the CVD process of silicon from silane, modeled according to the classical 16 species, 27 reactions chemistry model for this process as published by Coltrin et al. (1989).