1 ML Wetting Layer upon Ga(As)Sb Quantum Dot (QD) Formation on GaAs Substrate Monitored with Reflectance Anisotropy Spectroscopy (RAS)

Figure 1

Sketch of layer sequence and atomic force microscope (AFM) images of GaAs surfaces after GaSb growth with nominal coverages of 1-6 ML. The lateral scaling is equal in all cases, and the vertical/gray scaling is not. For a coverage of 1 ML no QD can be observed. For a nominal coverage of 6 ML the QD are too close to each other to be reckoned as completely separated. E.g., for the pyramidal QD and 3 ML nominal coverage the side length is 27 nm and the height amounts to 4 nm.