Atomic-scale Fluctuation of InAs-GaAs(001) Surface Reconstruction and Non-classical Nucleation of Quantum Dots(<Special Issue>Semiconductor Crystal Growth Mechanism studied by in-situ Observation Techniques)

Abstract

The growth of InAs quantum dots on GaAs(001) shows a new aspect of non-classical nucleation, namely the dynamic formation of preferred growth sites within the substrate. Using fully in situ scanning tunnelling microscopy - molecular beam epitaxy, we observe rapidly changing transitions between domains of different surface reconstruction a few nm in size. Nucleation of 3D islands is preferred on one particular reconstruction, blurring the line between heterogeneous and homogeneous nucleation as traditionally understood on a static substrate.