Patterning a surface on the nanometric scale by ion sputtering

Abstract
Surface etching by ion sputtering, besides producing equilibrium-oriented patterns similar to those obtained by molecular beam epitaxy (MBE), can also be used to pattern the surface along nonequilibrium orientations, thus extending the possibilities of MBE. By tuning the competition between ion erosion at grazing angles and diffusion-induced surface reorganization, it is, for example, possible to pattern a substrate characterized by a square symmetry with a well-ordered ripple structure running along any desired direction.