Comparison of effects produced on solid surfaces by bombardment with neutrals or ions in the keV range

The physical and chemical effects produced by bombardment with fast neutrals or ions of solid surfaces of different electrical conductivity have been studied by electron spectroscopy for chemical analysis (ESCA). The systems on which these effects have been compared are SnO2, PbO2, polystyrene and n-doped Si〈111〉. The first two systems were bombarded with particles (argon) which can only interact with the substrate by energy deposition, while polystyrene and silicon were bombarded with reactive particles (nitrogen). The general trend at the relatively high doses used here (1014-1017 particle cm-2) is that the observed effects are similar when using neutrals or ions. However, in the case of polystyrene and silicon, both bombarded with nitrogen particles, small but significant differences in the reaction kinetics have been found. Such differences are ascribed to a difference in reactivity between the surfaces bombarded with neutrals or ions.