Site-controlled lateral arrangements of InAs quantum dots grown on GaAs(001) patterned substrates by atomic force microscopy local oxidation nanolithography

Abstract

In this work, we present a fabrication process that combines atomic force microscopy (AFM) local oxidation nanolithography and molecular beam epitaxy (MBE) growth techniques in order to control both the nucleation site and number of InAs quantum dots (QDs) inside different motifs printed on GaAs(001) substrates. We find that the presence of B-type slopes (As terminated) inside the pattern motifs is the main parameter for controlling the selectivity of the pattern for InAs growth. We demonstrate that either single InAs QDs or multiple InAs QDs in a lateral arrangement (LQDAs) can be obtained, with a precise control in their position and QD number, simply by varying the fabricated oxide length along the [110] direction.