Computer simulation of single-crystal and polycrystal sputtering

Examination of the results of computer simulation of Cu single-crystal and polycrystal sputtering by 27 keV Ar ions started in Part I of the present work is continued. The spatial and energy distributions of all sputtered atoms and various sputtering components are analysed here. The incidence angles α = 45 deg and 85 deg are taken as examples. The sputtering is shown to be mainly near the <110> and <100> axes and also, especially in the case of glancing incidence, near a plane perpendicular to the ion beam. The mechanisms of predominant sputtering are discussed in detail. The importance of linear collision chains and correlated collisions of the incident ions with the atomic rows of a crystal lattice is emphasized. It is noted that bombardment of a crystal under semichanelling conditions is favourable for the target to be sputtered in the form of clusters. In connection with Harrison's recent remarks on Sigmund's sputtering theory, the relationship of the energy of sputtered atoms to the depth of their production in a crystal is examined. The mean depth from which the sputtered atoms are ejected has been found to be a nonmonotonic function of their energy. (author)