Molecular dynamics simulation of Al (001) surface magnetron sputtering of WS2 thin films

Abstract

WS2 is a two-dimensional solid lubricant with exceptional thermal stability. The WS2 thin films prepared by the magnetron sputtering method are effective in reducing friction and wear in critical components such as those used in aviation, aerospace, and military applications. The microscopic mechanism of magnetron sputtering significantly influences the properties and quality of these films. Therefore, it is essential to investigate the deposition mechanism of magnetron-sputtered WS2 thin films at the molecular level. In this paper, the effects of incident energy and incident angle on the morphology of Al (001) surface magnetron sputtering WS2 thin films were studied by molecular dynamics simulation, and the growth mode of Al (001) surface magnetron sputtering WS2 thin films was explored. The results reveal that the growth mode of magnetron-sputtered WS2 thin films on the Al (001) surface is a Stranski–Krastanov growth mode. With an increase in the incident energy, the film's surface roughness, thickness, and the atomic ratio of sulfur to tungsten (S/W) are decreasing. Additionally, for low incident energies (0.1–1.0 eV), a decrease in surface roughness without a corresponding decrease in film thickness was observed. Furthermore, with an increase in the incident angle, the surface roughness increases and the thickness of the film decreases, respectively. The study concludes that WS2 thin films at an incident energy of 0.7 eV and an incident angle of 0° exhibit optimal properties, with a surface roughness of 1.453 Å, a film thickness of 7.873 Å, and an S/W of 1.232.