Regrowth of self-assembled InAs quantum dots on nanohole and stripe templates

Abstract

Self-assembled InAs quantum dots (QDs) are grown on two types of templates by molecular beam epitaxy (MBE). A nanohole template is prepared by first growing InAs QDs on a GaAs substrate by a standard MBE process, then capping the QDs with a thin lattice-mismatched layer of GaAs. Subsequent annealing of the nanohole template results in a stripe template. We are able to transfer the patterns of self-assembled QDs onto these two types of templates: regrowth on the nanohole template results in uniform QDs situated in the nanoholes, while regrowth on the stripe template results in chains of QDs aligned along the stripes. Our results imply that self-assembled QDs can be grown onto in-situ prepared patterned substrates, with limited degree of randomness.