Three distinct regimes were observed by using real-time X-ray scattering to measure the surface morphology of (111) surfaces during sputter-erosion by 500eV Ar+ ions. These regimes were: 3-dimensional rough erosion at 20 to 60C, quasi layer-by-layer removal at 120 to 220C, and step retraction at temperatures above 270C. Sputtering at 20 to 60C led to pattern formation, with a characteristic spacing between features. The average separation between features increased, with time, according to a power law with an exponent of about 0.27. These observations were consistent with the predictions of a continuum model, for deposition, which included an Ehrlich-Schwoebel barrier to the interlayer diffusion of surface defects.

X-Ray Scattering Study of the Surface Morphology of Au (111) during Ar+ Ion Irradiation M.V.R.Murty, T.Curcic, A.Judy, B.H.Cooper, A.R.Woll, J.D.Brock, S.Kycia, R.L.Headrick: Physical Review Letters, 1998, 80[21], 4713-6