Selective Formation of Self-Organized InAs Quantum Dots Grown on Patterned GaAs Substrates by Molecular Beam Epitaxy

Abstract

We have studied the formation of self-organized InAs quantum dots (QDs) on patterned GaAs substrates. To enhance the migration of the atoms, the InAs QDs were grown by periodic supply epitaxy. For InAs growth on line patterns that were parallel to the [110] direction, the InAs QDs were selectively formed on the A-planes. Conversely, no selective formation of InAs QDs was observed on line patterns, that were parallel to the [110] direction. This can be explained by the stability of the In atoms on the A-steps; they are more stable because they have only one dangling bond, and the other three bonds are attached to As atoms below them. Therefore, accumulated InAs on the A-steps can form QDs at an early stage. The µ-photoluminescence properties of the InAs QDs were studied, and strong emissions from the InAs QDs on the patterned areas were observed even at room temperature. Further work on this issue may reveal possibilities for controlling the exact position of a few InAs QDs.