Chapter 5 - InAs Quantum Dot Formation Studied at the Atomic Scale by Cross-sectional Scanning Tunnelling Microscopy

Abstract

This chapter reviews that self-assembled quantum dots (QDs) have attracted much attention in the earlier years. These nanostructures are very interesting from a scientific point of view because they form nearly ideal zero-dimensional systems in which quantum confinement effects become very important. These unique properties also make them very interesting from a technological point of view. It explains that X-STM is used to study at the atomic scale the formation of self-assembled QDs. This technique allows determining the size, shape, and composition of the buried nanostructures and provides vital information to understand the QD formation process. The chapter also discusses the capping process, which is found to be a critical step in QD formation because it strongly modifies the QD structure. In its initial stage, GaAs capping induces leveling of the QDs to drastically decrease their height. During continuous capping, the QD leveling is quenched when the QDs become buried.