Nanoscratching of Metallic Thin Films on Silicon Substrate: a Molecular Dynamics Study

By using a molecular dynamics method, a computer simulation of a scratch test on a nanometer scale has been performed. The specimen is composed of four atomic layers of metallic atoms deposited on a substrate of 864 silicon atoms. The thin-film materials chosen were Al, Cu, Ti, and W. The critical load had a similar tendency to the interface energy of a heterogeneous junction, and the maximum friction constant coincided fairly well with adhesion strength. On the basis of our simulation results we propose methods for detecting the critical load of scratching and for estimating the bonding of the film–substrate interface.