Low pressure chemical vapor deposition of epitaxial silicon-germanium, epitaxial silicon and poly-silicon

A mathematical model is developed for a low pressure hot-wall chemical vapor deposition reactor used in the growth of epitaxial silicon-germanium, epitaxial silicon, and poly-silicon. The reactor is separated into three regions: the entry length, the annular region and the inter-wafer region. Reactant concentrations in both the entry length and the annular region are assumed to be functions of the axial position only, while reactant concentrations in the inter-wafer region are two-dimensional as diffusion in both the radial and axial directions is important. With the assumption of no gas phase reactions in the reactor, different deposition processes can be modeled with a similar algorithm using different surface reacton rates. The model relates deposition rates of these processes to processing environments such as temperature, pressure and reactor geometry. Modeling results are found to be in satisfactory agreement with experimental data.