Molecular dynamics simulation of atomic beam bombardment on solid surface

Molecular dynamics simulations are carried out to investigate the response of copper thin film which is subjected to the bombardment of an energetic monomer and cluster beams, which are utilized in microscale fabrication such as the focused ion beam (FIB) system. The results shows clearly the difference in the heat and mass transfer mechanism between monomer and cluster bombardments. In the case of monomer incidence with 1 keV, the projectile penetrates deeply into the target material. A ''hot spot'' is created inside the target material because of the energy transfer from the projectile to the target atoms In this region the atomic phase changes from solidlike to liquidlike. On the other hand, when cluster incidence consists of 32 atoms with 100 eV per atom, the energies are deposited on the surface of the target and are transferred mainly in oblique directions inside the target material rather than toward the cluster incidence.