Diffuse-interface model for nanopatterning induced by self-sustained ion etch masking

We construct a simple phenomenological diffuse-interface model for composition-induced nanopatterning during ion sputtering of alloys. In simulations, this model reproduces without difficulties the high-aspect-ratio structures and tilted pillars observed in experiments. We investigate the time evolution of the pillar height, both by simulations and by in situ ellipsometry. The analysis of the simulation results yields a good understanding of the transitions between different growth regimes and supports the role of segregation in the pattern-formation process.