NUMERICAL STUDY OF TRANSPORT PHENOMENA IN MOCVD REACTORS USING A FINITE VOLUME MULTIGRID SOLVER

A mathematical model for epitaxial growth in metalorganic chemical vapor deposition reactors (MOCVD) has been developed which is based on the conservation equations for mass, momentum, heat, and species including thermodiffusion and chemical reactions. The model was implemented in a finite volume numerical solution procedure for two-dimensional (plane and axisymmetric) laminar flows. Second-order central differencing was used to discretize both convection and diffusion fluxes. To speed up the convergence of the computations, a ''Full Approximation Scheme'' of a multigrid technique was employed. The growth of GaAs from trimethyl-gallium (TMGa), arsine, and hydrogen was considered where the deposition process is assumed to be in the transport-limited regime. The calculated deposition rates in the reactor were compared with experimental results from literature. The model gives accurate results for growth at subcritical Rayleigh numbers. Computational results show that the two-species model gives more accurate results compared with the one-species model without gas phase reactions. Deposition at the upper wall was found to have a remarkable influence on the growth rate of the film on the substrate.