Reverse epitaxy of Ge: ordered and facetted surface patterns

Abstract

Normal incidence ion irradiation at elevated temperatures, when amorphization is prevented, induces novel nanoscale patterns of crystalline structures on elemental semiconductors by a reverse epitaxial growth mechanism: on Ge surfaces irradiation at temperatures above the recrystallization temperature of 250°C leads to self-organized patterns of inverse pyramids. Checkerboard patterns with fourfold symmetry evolve on the Ge (100) surface, whereas on the Ge (111) surface, isotropic patterns with a sixfold symmetry emerge. After high fluence irradiations these patterns exhibit well developed facets. A deterministic nonlinear continuum equation accounting for the effective surface currents due to an Ehrlich-Schwoebel barrier for diffusing vacancies reproduces remarkably well our experimental observations.

6 pages, 5 figures

References in corpus (1)

• On the stabilization of ion sputtered surfaces

Cited by in corpus (5)

• Anisotropic nanoscale wrinkling in solid state substrates
• Nanoripple formation on GaAs (001) surface by reverse epitaxy during ion beam sputtering at elevated temperature
• Symmetry of surface nanopatterns induced by ion-beam sputtering: the role of anisotropic surface diffusion
• Measurement of Ehrlich-Schwoebel barrier contribution to the self-organized formation of ordered surface patterns on Ge(001)
• Unprecedented Severe Atomic Redistribution in Germanium Induced by MeV Self-Irradiation