Fabrication of InGaAs Quantum Wires and Dots by Selective Molecular Beam Epitaxial Growth on Various Mesa-Patterned (001)InP Substrates

Systematic growth experiments were undertaken for the successful formation of InGaAs/InAlAs quantum wires and dots on patterned InP substrates by selective molecular beam epitaxy (MBE). Multi layer test structures consisting of InGaAs and InAlAs alternate layers were formed on 7 different types of mesa patterns including stripe- and square-shaped mesas oriented along the [110], [110] and [100] directions. The growth led to the formation of sidewalls consisting of a variety of facets. Although these sidewalls were often rough or not uniform, the growth on the stripe-mesas along the [110] and [100] directions, and the growth on the square-mesas with (201) sidewall facets were found to be promising since they resulted in very smooth sidewall facets, cross-sectional and lateral uniformity, and good growth selectivity. Using these results, InGaAs quantum wires and dots were successfully formed.