Computer Simulation of Reactors for Chemical Vapor Deposition

化学气相沉积(CVD)工艺被大规模用于制备电子和光学固态器件的电子活性和绝缘层。CVD反应器中的流动、传热和传质过程以及化学反应对CVD工艺形成的器件的质量起着至关重要的作用。CVD反应器内的流体动力学特征是温度梯度大，气体性质强烈的温度依赖性，强迫和浮力诱导的联合对流，均相气相和非均相表面反应。CVD过程的准确模型可用于设计新的系统，并减少所需的探索性实验次数，这可能非常昂贵。这个第一阶段，小型企业创新研究项目包括一个总体计划的初始部分，该计划旨在为一些常见的CVD反应堆配置开发和验证准确和高效的三维数值模型。该模型的主要特点是：(1)在身体协调的网格上求解控制方程，以便能够准确地表示复杂的构型；(2)输运方程中对流项和扩散项的高阶表示；(3)求解耦合离散化方程的有效算法；(4)可变的物性公式，以便能够考虑重要的温度相关性；(5)求解共轭问题的能力，以便在不需要任何流固界面上的任意边界条件的情况下考虑反应器壁内的传导；(6)反应器壁温度分布的真实表示；和(7)完全灵活的代码结构，可以合并任何反应方案。预计最终产品将是实际CVD反应器中流动的精确计算模型。

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.