Shocks in Ion Sputtering Sharpen Steep Surface Features

Abstract

We report a regime of ion beam sputtering that occurs for sufficiently steep slopes. High slopes propagate over large distances without dissipating the steepest features. Both the propagation velocity and the dynamically selected slope are universal, independent of the details of the initial shape of the surface. The resulting behavior can be understood as the propagation of a shock front that self-selects a stable slope, as has been previously observed in thin-film fluid flows. Experiments confirm predictions of the theory. An important implication of the propagative behavior at high surface slopes is that a pattern can be fabricated at a large length scale and, through uniform ion irradiation, reduced to a smaller length scale while preserving, or even sharpening, the sharpest features.

The production, characterization and applications of nanoparticles in the textile industry

“…Although a wide variety of information about nanoparticles supported by a flat substrate can be obtained using SPM methods, there are a variety of tip artefacts that can influence the accuracy of the measurements. Work of Braga and Ricci [252] is devoted to recognizing and avoiding artefacts in AFM imaging. International standards committees (ASTM E42 and ISO TC201) have subcommittees working on relevant standards and guides to these effects [252].…”

“…Work of Braga and Ricci [252] is devoted to recognizing and avoiding artefacts in AFM imaging. International standards committees (ASTM E42 and ISO TC201) have subcommittees working on relevant standards and guides to these effects [252]. In material-sensing mode, the AFM can distinguish between different materials, providing spatial distribution information on composite materials with otherwise uninformative topographies.…”

Focused Ion Beam Microscopy and Micromachining

“…27 Other unusual effects of sputtering and redeposition on surface evolution continue to be discovered. 28,29 Nonetheless, progress is being made toward models that can predict surface evolution during sputtering and can be used to achieve desired sputter profiles (see the article by Langford et al in this issue).…”

Self-organized nanopatterning of silicon surfaces by ion beam sputtering

“…(7) and (8), arbitrary values of the slope are allowed for [215][216][217]. This has been shown to provide a good description for the propagation of high steps or ridges on Si targets [215,216], even leading to a fabrication method for patterns made of knife-edge ridges [217].…”