A molecular dynamics study of the deposition and the diffusion behaviors of Al on a Cu surface

The deposition and the diffusion behaviors of Al atoms on Cu surfaces of various orientations were investigated by using classical molecular dynamics simulations and molecular static calculations. Al atoms with a kinetic energy of 0.1 eV were deposited at room temperature. On the Cu(001) surface, the deposited Al atoms tend to agglomerate only with adjacent atoms. In the case of the Cu(111) surface, surface diffusion of Al atoms is significant even as a time scale between two consecutive depositions (5 ps). Most deposited atoms are, thus, agglomerated near the surface step. In contrast, Al atoms deposited on Cu(011) hardly diffuse on the surfaces but intermix with the Cu atoms, resulting in an atomistically rough interface. These behaviors are consistent with changes in the activation barrier for a possible kinetic process that depends on the orientation of the substrate.