Limiting thickness versus epitaxial-growth temperature in molecular-beam epitaxy

Abstract

We show that, as a direct consequence of dynamical scaling of surface roughness arising due to the kinetic nature of molecular-beam-epitaxial growth, epitaxial growth may be characterized by a limiting thickness beyond which a growing film is rough. We find this limiting thickness to be an exponential function of growth temperature because of the activated nature of atomistic surface diffusion. We reconcile the notion of limiting thickness with that of the epitaxial growth temperature as a manifestation of a surface-diffusion-induced crossover phenomenon.