Morphological stability of facet growth on nonplanar substrates

We study the morphological stability of layer growth by chemical vapor deposition onto a nonplanar substrate patterned with a facetted groove. Our analytic treatment indicates that, except under conditions of very modest supersaturation, diffusion effects in the gas phase generally preclude the stable growth of crystallographic facets that form the sidewalls of the groove. Instead, heterogeneous nucleation and the kinetics of step tIow combine to promote the evolution of an initially perfect facet into a stably propagating vicinaZ surface. Under more diffusion-limited conditions, even these “facets” do not survive and a characteristic rough morphology results.