Angle-dependent sputter yield of rippled surfaces

Atomistic (binary-collision) simulation is used to study the sputter yield of rippled C and Si surfaces bombarded with Ar and Ga ions in a wide range of incidence angles and energies. This study was motivated by conflicting theoretical predictions of results when the ion energy is varied. Most simulations refer to a sinusoidal ripple topography with h/lambda = 0.05-0.15, where h and lambda are the amplitude and wavelength of ripples, respectively. Results are compared with Monte Carlo simulation based on Sigmund's continuum model of ion sputtering and not tied to a specific ion-target combination. Both types of simulation do not confirm a strong suppression of the angular variation in the sputter yield from rippled surfaces with increasing ion energy, predicted theoretically (Makeev and Barabasi, 2004).