Surface kinetics and roughness on microstructure formation in thin films.

Abstract

Formation of columnar structures in a thin film grown by direct deposition was studied with a full molecular-dynamics simulation. The effects of substrate temperature, beam energy, and surface roughness on columnar structure formation were investigated. Small surface perturbations evolve into a columnar structure with the column orientations exhibiting the empirical tangent relationship. These microstructures are formed only at low substrate temperatures (below half the melting temperature). The columnar growth mechanism is found to be rather insensitive to the beam energy, except that the column width becomes thicker with increasing beam temperature.