Microscopic insight into the sputtering of thin polystyrene films on Ag{111} induced by large and slow Ar clusters

Molecular dynamics computer simulations were employed to model the bombardment of Ag{111} covered with a monolayer of sec-butyl-terminated polystyrene tetramer (PS4) molecules by the impact of large and slow clusters. The investigated surface was bombarded with clusters composed of between hundreds to 29 000 Ar atoms having a very low kinetic energy per atom (0.1-40 eV). The sputtering yield of molecular species and their internal, angular, and kinetic energy distributions were analyzed. The simulations demonstrated quite clearly that the physics of ejection by these large and slow clusters is distinct from the ejection events stimulated by the popular SIMS clusters, C-60, Au-3, and SF5.