Real-time Observation of Nucleation and Evolution of InAs Quantum Dots on GaAs(001) During MBE

摘要

Real-time observation of self-assembled (SA) InAs quantum dot (QD) growth on GaAs(001) by MBE has been performed. Through transient measurements on reflection high energy electron diffraction (RHEED) specular beam, we obtain information about nucleation and evolution of the QDs in situ, in contrast to most previous reports that required growth interruption. Based on the observation, we have been able to distinguish processes that are dependent and independent of growth rate. In addition, the results reveal that surface migration of In/As atoms and their incorporation into QDs, with the aid of the wetting layer, can be observed. We also provide a quantitative discussion on these processes.