Quasi-thermodynamic model of SiGe epitaxial growth

A global model of SiGe chemical vapor deposition (CVD). accounting for the coupled heat and radiation transfer, species transport, surface reactions, and elastic strains in the layer, is developed. The surface kinetics and th e strains are described within the quasi-thermodynamic approach considering the adsorbed layer to he in the: quasi-equilibrium with the crystal lattic e. The model is verified using a wide range of experimental data and then i s applied to study of SiGe growth in the 200mm wafer Centura reactor from a mixture of SiH4, GeH4, and H-2. The temperature, species concentrations, a nd velocity vector fields in the reactor, the growth rate and C;e fraction distributions along the wafer are obtained. The model predicts slowing down the growth and shift of the alloy composition towards Ge at high dilution of the precursors by hydrogen. (C) 2001 Elsevier Science B.V. All rights re served.