Modeling of molecularhyphen;beam epitaxy and metalorganic vaporhyphen;phase epitaxy on nonplanar surfaces

摘要

A model allowing a consistent description of growth evolution on nonplanar surface by molecularhyphen;beam epitaxy and metalorganic vaporhyphen;phase epitaxy is presented. It is shown that the elemental kinetic processes (surface migration, incorporation, and desorption) are reduced to an equation of continuity for an atomic flow on a growing surface. In metalorganic vaporhyphen;phase epitaxy this continuity equation is coupled with the diffusion equation in vapor phase, permitting to calculate selfhyphen;consistently the density distribution of reactant species in vapor and of the adatoms in the surface layer. In the model, anisotropic properties of growth are introduced by taking into account the surface diffusion around the atomic steps. The formulation of the model is based on the discrete form of the continuity equation (rather than the differential form) and therefore allows description of the growth behavior including the development of sharp facet edges. The method of simulation for nonplanar growth is illustrated in detail. thinsp;