Molecular Dynamics Simulation on Microstructure and Deformation Properties Related to Porosity in Al Thin Film Sputtered on Si Substrate

Abstract

A material system of Al sputtered on crystalline Si was dealt with as one of the simple material models for semiconductor material systems. To investigate qualitative properties of sputtered films on an atomic scale, simulations were conducted by a molecular dynamics (MD) method using two film models; i.e. a deposition model based on MD simulations of sputtering process and a crystal model using a crystalline Al film instead of a deposited one. The surface roughness and porosity, which are defined in this work, were found to decrease with an increase in the incident energy of atoms. Relationships between tensile deformation properties and porosities in simulated thin films were also investigated. Although the porosity was found to affect the tensile strength in the direction parallel to the substrate surface, it was revealed that the tensile strength in the direction perpendicular to the substrate surface was hardly influenced by the difference in the porosity.