Study of argon characteristics in ion physical vapor deposition using molecular dynamics simulation

This article uses molecular dynamics simulation to investigate the role of Ar ions in the ion physical vapor deposition (IPVD) process for different Ar⁺-to-Cu⁺ ratios, and to analyze the influence of different Ar⁺-to-Cu⁺ ratios on the trench filling morphology. Also compared are the trench filling morphology observed for the IPVD process with that found in the conventional collimated magnetron deposition process. The molecular dynamics simulation includes a trench model and a deposition model, and uses the many-body, tight-binding potential method to represent the interatomic force acting among neutral atoms. The interatomic force acting between the ions and the neutral atoms is modeled by the pairwise Moliere potential method. The simulation indicates that the incident Ar ions influence the trench filling mechanisms in two significant ways; peeling of the cluster atoms, which promotes migration of the cluster atoms along the sidewall, and breaking of the bridge which forms when two clusters of atoms join. Both phenomena are beneficial since they promote a more complete filling of the trench.