MD simulations of the cluster beam deposition of porous Ge

The low-energy cluster beam deposition of Ge clusters on a Si surface was simulated using classical molecular dynamics. In an effort to find a suitable energy range to construct porous Ge films, the porosity of the resulting layers was mapped as a function of deposition energy. It was discovered that the energies of interest to produce porosities in the range of 30% to 70% were between about 10 meV and 500 meV per atom. Also, it became clear that the number of deposited clusters must be above 40 for the calculated porosities to be accurate. In addition, transmission electron microscope image simulations were performed on the deposited samples, and images of porous and non-porous layers were found to be distinctly different.