Molecular dynamics simulation of the effect of incident energy on the growth of Au/Au (111) thin film

Abstract

The low-energy bombardment on Au (111) surface by Au atoms is studied by molecular dynamics (MD) simulation. The atomic interaction potential of embedded atom method is used in the simulation. The incident-energy effects on the morphologies and the surface roughness values of the deposited films are observed and summarized. The incident energy (Ein) varies from 0.1 eV to 50 eV. The transition of incident energy dependence occurs when the energy value is about 25 eV. The incident energy of about 25 eV is the sputtering threshold of Au (111) substrate. When the incident energy is lower than 25 eV, no atoms can be implanted into the depth beyond the second layer and all atoms are in face-centered cubic (111) arrangement without dislocation. The surface roughness decreases with the increase of the incident energy. For the case of Ein≥25 eV, the deposited atoms reach the third layer. When the number of atoms deposited in a substrate layer reaches about half the total number of atoms in this layer, the deposited atoms could go throgh this laer and enter into a deeper layer in the substrate. Surface roughness increases with the increase of the incident energy, and the energetic deposition can produce defects in both substrate and film.