Surface modification with ionised cluster beams: Modelling

Impacts of accelerated cluster ions which consist of hundreds of atoms on a solid surface have shown new surface smoothing and roughening effects. Hyb rid Molecular Dynamics (MD) and a two-dimensional MD method were used to si mulate rapid collision processes at the target impact zone and the subseque nt thermalization. Gas clusters impacting on metal and semiconductor target surfaces have been considered to study the ripple formation under irradiat ion with oblique cluster beams. The dynamics of surface modification is sim ulated by using a discrete model which contains crater formation and surfac e relaxation. The continuum description of a surface relaxation is based on a dynamics equation for surface heights containing viscous flow, surface t ension, surface diffusion, and crater formation terms. Comparison of the re sults of the simulation with experimental data shows qualitative agreement. (C) 1999 Elsevier Science B.V. All rights reserved.