Investigation of growth mode and surface roughness during homoepitaxial growth of silver metal using kinetic Monte Carlo simulation

Abstract

In this work, a kinetic Monte Carlo (KMC) method for deposition is investigated to simulate the homoepitaxial growth of silver metal under experimental conditions. On-lattice and coarse-graining approximations are applied. KMC method is an ideal tool for simulating the Physical Vapor Deposition (PVD) process, which involves deposition and diffusion. The method accounts for surface diffusion processes, in addition to nearest-neighbor hopping and including Schwoebel-Ehrlich (SE). The SE mechanism effect on the growth mode and influences of substrate temperature and deposition rate on surface roughness have been studied in detail. The simulation results show when the Schwoebel hops are active, the growth mode is Frank-van der Merwe (2D). Furthermore, when the Schwoebel hops are not active, the growth mode is Volmer-Weber (3D). In addition, when increasing the deposition rate, the surface roughness increases due to the size of islands increase. Besides, when the temperature increases, the surface roughness decreases because the islands formed are transformed into a large cluster.