The fate of a cluster colliding onto a substrate: Dissipation of translational kinetic energy

The fate of clusters emitted onto a substrate falls into several categories including repulsion, soft landing, migration, and explosion, depending on the interaction between the cluster and the substrate. This dynamic behavior of the clusters controls thin-film formation processes from clusters such as cluster ion beam deposition and chemical vapor deposition. Here we describe the collision processes of both Al and Au clusters with a kinetic energy of ∼0.56eV/atom onto an amorphous SiO₂ substrate studied by molecular dynamics simulation, focusing on the dissipation of translational kinetic energy during the collision process. The simulation elucidated that the activation of thermal vibrational energy of the substrate promoted the sticking of the colliding clusters on the substrate. This result suggests that the dissipation of the translational kinetic energy of the colliding cluster is one of the factors that determine the structure formed on a substrate from vapor phase.