THERMOCHEMICAL AND MASS-TRANSPORT MODELING OF THE CHEMICAL-VAPOR-DEPOSITION OF SI1-XGEX

The purpose of this article is to present, for the chemical vapour deposition process, mass transport models with near local thermochemical equilibrium imposed in the gas-phase and at the deposition surface. The theoretical problems arising from the linking of the two approaches, thermodynamics and mass transport, are shown and a solution procedure is proposed. As an illustration, selected results of thermodynamic and mass transport analysis and of the coupled approach showed that, for the deposition of Si1-xGex solid solution at 1300 K (system Si-Ge-Cl-H-Ar), the thermodynamic heterogeneous stability of the reactive gases and the thermal diffusion led to the germanium depletion of the deposit.