Size-Limiting Effect of Site-Controlled InAs Quantum Dots Grown at High Temperatures by Molecular Beam Epitaxy

We have investigated the site-controlled growth of InAs quantum dots (QDs) by using atomic-force-microscope (AFM)-assisted anodic oxidation. It is found that the morphology of the site-controlled QDs strongly depends on the growth temperature, $T_{\text{g}}$; when QDs are grown at $T_{\text{g}}\leq 480$ °C, the obtained QDs are much larger than the nanoholes prepared by AFM oxidation. In contrast, when QDs are grown at $T_{\text{g}} = 520$ °C, the diameter of the QDs is limited by that of nanoholes and is almost unchanged with varying InAs supply. The single-layer QD array grown at 520 °C showed good optical properties and uniformities.