Formation of Semiconductor Vertical Quantum Barriers by Epitaxial Growth on Corrugated Surfaces

The relation hip between growth rate anisotropy, capillarity and entropy of mixing effects, and self-ordering of semiconductor alloy nanostructures grown on nonplanar surfaces, is investigated theoretically and experimentally. It is shown that self-ordered nanostructures enriched by one component of the alloy or the other are formed, depending on the sign of the surface curvature and the growth rate anisotropy. The formation of Al-rich AlxGa1-xAs vertical quantum barriers on convex surfaces with a particular sign of the growth rate anisotropy is experimentally demonstrated.