Quantitative monitoring of InAs quantum dot growth using X-ray diffraction

• We used X-ray diffraction to perform in situ monitoring of MBE-grown QDs.
• The QD lateral and vertical sizes were determined as a function of growth time.
• The total volume of QDs was found to increase at a similar rate over the range of 450–480 °C.
• Significant mass transport is observed from the wetting layer and substrate.

Synchrotron X-ray diffraction has been applied to the in situ monitoring of the molecular beam epitaxial growth of self-assembled InAs/GaAs(001) quantum dots (QDs). As well as the strain distribution inside QDs, the lateral and vertical size of QDs was determined as a function of growth time. In combination with post-growth atomic force microscopy, the evolution of the total volume of QDs was evaluated. It was found that the QD volume increases at a similar rate over the temperature range of 450–480 °C. A significant mass transport from the wetting layer and the substrate was confirmed.