Molecular dynamics simulations of surface smoothing and sputtering process with glancing-angle gas cluster ion beams

Surface modification processes with glancing-angle large gas cluster irradiation were studied by molecular dynamics simulations. The MD simulation of an Ar-2000 gas cluster impacting on Si(1 0 0) substrate with small Si-4096 block structure attached on the surface was performed. The MD result has shown that, when the Ar cluster impacts on the target at 20 keV of total acceleration energy and at 80 degrees of incident angle, the incident cluster slides on the target surface without creating surface damage and most of the constituent atoms in the cluster collide with the sidewall of the surface block. Up to 10 keV of kinetic energy of the incident cluster was transferred to the target irregular structure, which results in the sputtering or stretching of the surface block and the target surface is smoothed. This characteristic surface modification effect was observed when the surface block is located farther than 200 angstrom from the point where the incident cluster contacts with the target surface. (c) 2007 Elsevier B.V. All rights reserved.