Intrinsic and Mn doped InAs quantum dots studied at the atomic scale by cross-sectional scanning tunneling microscopy

Cross-sectional Scanning Tunneling Microscopy (X-STM) is an ideal tool to study the structural properties of semiconductor nanostructures, such as InAs self-assembled quantum dots (QDs) and the properties of individual doping atoms at the atomic scale. The technique allows for a precise determination of the size, shape and composition of overgrown semiconductor nanostructures which can be part of a (complex) multilayer structure. In this paper we discuss our recent results on InAs QD structures that were capped by various methods in order to control their size and shape. We will show that the capping process does strongly affect the final QD structure and thus forms a very important step in the dot formation process. Recently people have started to investigate magnetically doped QDs. We have used our X-STM technique to study the incorporation of single Mn-impurities in InAs/GaAs QDs.