MOLECULAR-DYNAMICS SIMULATION OF ATOMIC-BEAM BOMBARDMENT ON SOLID-SURFACE

Molecular dynamics simulations are carried out to investigate the resp onse of copper thin film which is subjected to the bombardment of an e nergetic monomer and cluster beams, which are utilized in microscale f abrication such as the focused ion beam (FIB) system. The results show s clearly the difference in the heat and mass transfer mechanism betwe en 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 e nergy transfer from the projectile to the target atoms In this region the atomic phase changes from solidlike to liquidlike. On the other ha nd, when cluster incidence consists of 32 atoms with 100 eV per atom, the energies are deposited on the surface of the target and are transf erred mainly in oblique directions inside the target material rather t han toward the cluster incidence.