Molecular dynamics study of roughness and stress evolution using a Lennard–Jones potential

Abstract

A three-dimensional molecular dynamics (MD) simulation is proposed to study the film growth, roughness and stress evolution during atom deposition on the (100) plane of a fcc regular crystal. We use the cubic system with an x–y periodic boundary condition. At the bottom we have an atomic surface and at the top a reflecting wall. The model uses the Lennard-Jones potential to describe the interatomic forces. The simulation results show that the film grows with the Volmer–Weber mode and exhibits specific curve shape of the stress evolution. The mean biaxial stress obtained during the simulation attains a local tension maximum at a coverage of two monolayers. The stress in the normal direction is smaller than the biaxial stress. The main contribution to the stress in the film arises from the first monolayer. The curves describing roughness possess maximum values at the same substrate coverage. The dependence of the roughness on the temperature is examined.