Both the formation and migration energies of a single vacancy migrating intra- and inter-layer of the CuAg-terminated (001) surface or Cu-terminated (001) surface for Cu3Ag ordered alloy have been calculated by using the modified analytical embedded-atom method (MAEAM) with the molecular dynamics (MD) method. The surface effects on the vacancy formation and migration are all down to 6L for the CuAg-terminated (001) surface, but is respectively down to 5L and 6L for the Cu-terminated (001) surface. The vacancy energetically formed in the 1L. There is a vacancy aggregation tendency in the 1L as well as in the bulk the Cu vacancy is easier to be formed than the Ag vacancy.

The self-diffusion in very thin Cu (001) film that formed by 2~11 atomic layers have been studied by using modified analytic embedded atom method (MAEAM) and a molecular dynamic (MD) simulation. The vacancy formation is the most easily in of Cu (001) thin film formed by any layers. The vacancy formation energy 0.5054eV in of the Cu (001) thin film formed by layers is the highest in all the values in the ones that formed by layers. The vacancy in and 3 is easily migrated to layer, and the vacancy in is easily migrated in intra-layer, and the vacancy in is easily migrated to when the corresponding atomic layer is existed. The vacancy formation and diffusion will not be affected by the atomic layer when the Cu (001) thin film is formed by more than ten layers ().