SURFACE-MORPHOLOGY DEVELOPMENT DURING ION SPUTTERING - ROUGHENING OR SMOOTHING

We report on STM studies of ion-sputtered surfaces, applying sputterin g conditions which were shown to produce a relatively smooth surface. The height correlation function was calculated for the nickel layer in both the as-received and sputtered conditions. The large-scale roughn ess of the as-received specimen was reduced by ion sputtering accordin g to expectations derived from Auger depth profiling. On the other han d, the small-scale roughness was increased due to sputtering. Self-aff ine scaling regions are identified, and the exponents are compared to theoretical and numerical results.