Modeling of film growth by cluster deposition: The effect of size and energy

The density of cluster-assembled thin films depends heavily on the size of the deposited clusters as well as the energy with which they impact the substrate. Using molecular-dynamics simulations we have quantitatively studied variations in the density of thin films grown by deposition of clusters, with diameters between 1 and 9 nm, and at energies ranging from 2 meV to 10 eV per cluster atom. A model explaining the behavior of smaller clusters is presented, and a threshold limit in cluster size, where deviation from this model occurs, is determined. The deviation is shown to be due to a lessened sintering between clusters.