Kinetic Monte Carlo simulation of Cu thin film growth

Abstract

A three-dimensional kinetic Monte Carlo technique has been developed for simulating the growth of thin Cu films. The model involves incident atom attachment, surface diffusion of the atoms on the growing surface and atom detachment from the growing surface. A significant improvement in calculation of activation barriers for the surface atom diffusion on the growing film was made. The related effects caused by surface atom diffusion were taken into account. The results showed that there exist a transition temperature T t at a certain deposition rate. When the substrate temperature approaches T t, the growing surface becomes smoother and the relative density of the films increases. The surface roughness minimizes and the relative density saturates at T t. The surface roughness increases with increased substrate temperature when the temperature is higher than T t. T t is a function of the deposition rate. The influence of the deposition rate on the surface roughness is dependent on the substrate temperature. The simulation results also showed that the relative density decreases with increasing deposition rate and average thickness of the film.