Topography evolution mechanism on fused silica during low-energy ion beam sputtering

In this study, the topography evolution of fused silica surfaces during low-energy ion beam erosion has been investigated depending on the ion incidence angle and with focus on the importance of the initial surface topography. Ripple prepattern, also prepared by ion beam erosion, that exhibits an anisotropic surface with adjustable surface amplitudes and gradients was utilized. Based on experimental results that confirm smoothing and patterning behavior, gradient-dependent sputtering is identified being the dominant topography evolution mechanism.