Multi-length scale modeling of CVD of diamond - Part II - A combined atomic-scale/grain-scale analysis

Chemical vapor deposition of polycrystalline diamond films is studied by combining an atomic-scale kinetic Monte Carlo model with two (one three-dimensional and one two-dimensional) grain-scale models. The atomic-scale model is used to determine the growth rates of (111)- and (100)-oriented surface facets, the surface morphology of the facets and the extent of incorporation of the crystal defects. Using the atomic-scale modeling predicted growth rates for the (111)- and (100)-oriented facets, grain-scale modelling is carried out to determine the evolution of grain structure, surface morphology and crystallographic texture in the polycrystalline diamond films. It is found that depending on the relative growth rates of the (111)- and (100)-oriented facets, which can be controlled by selecting the CVD processing conditions, one can obtain either < 110 >-textured films with a relatively smooth faceted surface or < 100 >-textured films with a highly pronounced deep facets. In both cases, however, the film surface is composed entirely of the < 111 > facets. This findings are found to be fully consistent with the available experimental results. (C) 2000 Kluwer Academic Publishers.