Formation of InAs Dots on AlGaAs Ridge Wire Structures by Selective Area MOVPE Growth

Abstract

We investigate the formation of InAs quantum dots (QDs) on the top of AlGaAs ridge wire structures along the [110] direction by selective-area metalorganic vapor phase epitaxy (SA-MOVPE) and study their size distribution. It is found that the size distribution of QDs depends on the top width W of AlGaAs wires and growth amount θ of InAs. InAs dot size across the AlGaAs wires are limited by W and it becomes uniform for narrower W. In contrast, the size along the wire exhibits non-uniformity, particularly for narrower W and large θ. In addition, the shapes of InAs dot change depending on W. The results are discussed based on the diffusion of In from facets and masked area and the coalescence of QDs.