New approach to computer simulation of thin film deposition

Abstract

A 3D atomistic thin film deposition model has been successfully developed. The effect of the atomic mobility on substrate and film surface has been studied by using the model that simulates 3D thin film images, surface profiles and cross-sectional area pictures. In addition, quantitative results of surface RMS roughness, average film thickness, atomic coordination number and its distribution, and solid fraction of the deposited thin films are obtained from the simulations. When the film surface mobility increases from 0.3 to 3.0, RMS roughness decreases from 6.5 to 1.1, solid fraction increases from 0.27 to 0.46 and average film thickness decreases from 40 to 28 due to the diminishing of the voids within the film. The FWHM of the atomic coordination distribution becomes narrower indicating the increased degree of crystallization. With the increase in surface mobility crossing the boundary 1.5, the film evolves from a porous or loose columnar structure with voids to a densely packed fibrous grain structure which can be categorized by the zone structure models.