Molecular dynamics simulation on microstructure and deformation propertiesrelated to porosity in Al thin film sputtered on Si substrate

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