Substrate-dependent deposition of Cu thin films by molecular dynamics simulations

Polyethylene terephthalate (PET)/Cu composite films simultaneously exhibit the merits of flexibility, light weight and excellent electrical conductivity, and thus have potential applications in 5G technology. Although PET/Cu films have been prepared by available experiments, few studies have further provided an atomic-scale understanding of these deposition processes. Here, the growth of Cu thin films on Cu and PET substrates has been carried out by molecular dynamics (MD) simulations and vacuum evaporation experiments. A detailed comparison of surface roughness, crystal structures and interfacial adhesion for Cu films deposited on these two substrates has been made. A conclusion has been achieved that Cu films deposited on the PET substrate exhibit lower surface roughness and stronger adhesion than those on the metal substrate. This investigation will provide a deep understanding of the substrate-dependent deposition performance of metal thin films.