Rapid Coarsening of Ion Beam Ripple Patterns by Defect Annihilation

Abstract

Ripple patterns formed on Pt(111) through grazing incidence ion beam erosion coarsen rapidly. At and below 450 K coarsening of the patterns is athermal and kinetic, unrelated to diffusion and surface free energy. Similar to the situation for sand dunes, coarsening takes place through annihilation reactions of mobile defects in the pattern. The defect velocity derived on the basis of a simple model agrees quantitatively with the velocity of monatomic steps illuminated by the ion beam.

Ion-Induced Nanoscale Ripple Patterns on Si Surfaces: Theory and Experiment

“…Figure 7(a) and Figure 10(b)). This is in contrast to other experimental systems like Pt(111) surfaces under grazing incidence sputtering where rapid coarsening proceeds due to the annihilation of defects [109]. …”

Pattern formation on Ge by low energy ion beam erosion

“…For somewhat smaller ion incidence angles, most ions are still reflected in the forward direction and result in a distinct forward sputtering of initial topographic defects, especially at the upstream side of concave surface regions (depressions). The defect size grows in the direction of ion beam, probably accompanied by a guiding of ions along the defects, similar to the formation of perpendicular mode ripples on metallic surfaces at 83 • via a network of coalesced elongated vacancy islands [66,67].…”

Nanoripple formation onTiO2(110)by low-energy grazing incidence ion sputtering

“…20 This results in step arrays parallel to the beam and subsequent formation of ripples whose separation tend to increase with irradiation duration. 21 The studies reported here on TiO 2 are the first studies of this kind on a metal oxide. Previous studies of structure formation by grazing ion beams concentrated on metal surfaces [17][18][19]21,22 and ionic crystals such as CaF 2 ͑111͒ 15, 16 and KBr͑001͒.…”

“…21 The studies reported here on TiO 2 are the first studies of this kind on a metal oxide. Previous studies of structure formation by grazing ion beams concentrated on metal surfaces [17][18][19]21,22 and ionic crystals such as CaF 2 ͑111͒ 15, 16 and KBr͑001͒. 23 While the studies on Pt͑111͒ by the Michely group are comprehensive, the main question this present study addresses is if the same processes are applicable to more complex materials such as covalent/ionic bonded oxides, i.e., materials for which single-crystal wafers have potential applications, such as thin-film substrates.…”