Self-assembly of Ge quantum dots on silicon : an example of controlled nanomanufacturing

Abstract

We have grown Ge dots by physical vapor deposition on step bunched Si(111), vicinal Si(100) and oxidized Si(100) surfaces. A control of their one- and two-dimensional ordering was achieved through the combination of top-down patterning techniques (Focused Ion Beam milling) and naturally occurring instabilities. We studied the growth kinetics and self-organization of the islands using Scanning Tunnelling Microscopy in UHV and Atomic Force Microscopy, and we used a software routine to analyze the in-plane ordering of the islands on selected images. We focused on the study of the first nucleation stages of the dots, and attempted to correlate the observed behavior with the properties of high-miscut vicinal Si(100) surfaces. The relevance of this research to quantum-dots based technology is discussed.