ASSEMBLING STRAINED INAS ISLANDS BY CHEMICAL BEAM EPITAXY

We report on coherently strained InAs quantum-dots grown by chemical b eam epitaxy on GaAs. The morphological phase transition of the InAs la yer from two-dimensional to three-dimensional was characterized with r eflection high-energy electron diffraction. The transition is found to be quasi-equilibrium in the slow deposition regime studied, to be app roximately linear in InAs thickness, and to be suppressed both by high er temperature and As pressure. Patterned substrates were used to asse mble the dots in specific locations. Conditions were found to align do ts in chains of several-mu m length, to place small numbers of dots in holes, and to grow riots only within patterns but not on adjoining fl at surfaces. When capped with GaAs, the islands are optically active.