Ion-beam induced generation of Cu adatoms on Cu(100)

Low-energy ion scattering was used to study on-beam induced adatom generation during irradiation of a Cu(100) surface with 6 keV Ne ions at a sample temperature of 60 K. It was found that the number of adatoms produced per incoming ion decreases from an average of 3.5 to a saturation level of 1.8 after prolonged irradiation. Two mechanisms are believed to contribute to the adatom generation: ion-beam induced atom-replacement sequences and diffusion of self-interstitial atoms to the surface. From the adatom production as a function of irradiation dose the relative contributions of the two mechanisms were determined.