Chemical vapor deposition (CVD) processes are used on a large scale for the preparation of electronically active and insulating layers for electronic and optical solid state devices. The flow, heat and mass transfer processes, and chemical reactions in a CVD reactor play a critical role in the quality of devices formed by CVD processes. The fluid dynamics in a CVD reactor is characterized by large temperature gradients, strong temperature dependence of the gas properties, combined forced and buoyancy-induced convection, and homogeneous gas phase and heterogeneous surface reactions. Accurate models of CVD processes can be used to design new systems and decrease the number of exploratory experiments needed, which may be very expensive. This Phase I, Small Business Innovation Research project consists of the initial portion of an overall program to develop and validate an accurate and efficient three- dimensional numerical model for some common CVD reactor configurations. The main features of the model will be: (1) solution of the governing equations on a body-conforming grid so that complex configurations can be accurately represented; (2) a higher-order representation of the convection and diffusion terms in the transport equations; (3) an efficient algorithm for the solution of the coupled discretization equations; (4) variable physical property formulation so that the important temperature dependence can be taken into account; (5) ability to solve conjugate problems so that conduction in reactor walls can be considered without requiring any arbitrary boundary conditions at fluid-solid interfaces; (6) a realistic representation of the reactor wall temperature distribution; and (7) completely flexible code structure so that any reaction scheme can be incorporated. The end product expected will be an acurate computational model for flow in practical CVD reactors.
