Simulation of faceted film growth in two-dimensions: microstructure, morphology and texture

Abstract

A series of simulations of the growth of polycrystalline, faceted films from randomly oriented nuclei in two spatial dimensions was performed. The simulations track the motion of all corners where facets from the same grain and different grains meet. Results are presented on the temporal evolution of the mean grain size, grain size distribution, surface roughness, crystallographic texture and growth zones as a function of α, a parameter describing the relative facet velocities. The mean grain size and r.m.s. surface roughness are shown to be a parabolic function of the film thickness, in agreement with experiment and theoretical results. The grain size distribution is temporally self-similar when scaled by the mean grain size and has the form of a gamma distribution. The crystallographic orientation distribution (i.e. texture) is Gaussian, peaks at an α-dependent orientation and the peak sharpens during film growth. The peak position is well described by the largest radius vector of the appropriate idiomorph in two and three dimensions. The grain size, roughness and texture evolution are intimately linked. This type of simulation may be used to examine the evolution of the microstructure of any film which exhibits faceted growth with prescribed facet velocities.