Effect of GaAs polycrystal on the size and areal density of InAs quantum dots in selective area molecular beam epitaxy

Abstract

Selective growth of self-assembled InAs/GaAs quantum dots (QDs) is achieved by molecular beam epitaxy (MBE) utilizing dielectric masks on GaAs substrates. We find that polycrystalline deposits on the mask due to non-ideal growth selectivity between the mask and the epitaxy induce a significant modification of the QD height and areal density in their neighborhood. The results show an effective method to achieve selective area QD growth by using a dielectric mask and altering the degree of selectivity through control over the MBE growth conditions in a pulsed deposition mode.