A surface kinetics model for the growth of Si1− x Ge x films from SiH4/GeH4 mixtures

A model has been developed that semiquantitatively describes the kinetics of Si1−xGex alloy deposition over a wide range of temperatures in the absence of gas-phase chemistry. The salient feature of the model is that the kinetics of germane and silane deposition are treated as parallel processes, each with an adsorption step in series with a hydrogen desorption step. The two processes are coupled by competition for sites in the adsorption process, and fast equilibration between silicon and germanium hydride on the surface. The model is fit to, and compared with, data available in the recent literature.