Ion-Sputter Induced Rippling of Si(111)

Abstract

The morphology of ion sputtered Si(111) surfaces at glancing angles and elevated temperatures was studied by AFM. Under particular ion beam and sample conditions, the morphology of the surfaces was found to be rippled, with roughly sinusoidal-shaped bumps. This observation is in agreement with predictions of Bradley and Harper, and is similar to experiments performed by Chason et al. on germanium. Observation of the temporal evolution by stopping growth and performing microscopy suggests that a steady-state rippled morphology develops by coalescence of oblong islands. The wavelength of the ripples can be controlled up to about 600 nm, with amplitudes up to 60 nm. This observation creates an opportunity to make nanostructured surfaces for the study of crystal surface dynamics.