Controlled ordering and positioning of InAs self-assembled quantum dots

Abstract

An experimental approach has been developed to control the formation of InAs self-assembled islands. A lithographically defined mesa lattice on the surface was used to control the growth kinetics and island nucleation. Two distinct island formation regimes were observed from InAs islands grown on patterned GaAs (100) substrates. In the case of direct growth on patterned substrates, a type I islanding was observed, in which all the islands formed between mesas. Incorporating a stressor layer into the regrowth on the patterned substrate yielded a type island nucleation, where all the islands nucleated on top of the mesas. The possible mechanisms involved in the long range ordering and positioning of islands are discussed.