IN-SITU FABRICATION OF 3-DIMENSIONALLY CONFINED GAAS AND INAS VOLUMESVIA GROWTH ON NONPLANAR PATTERNED GAAS(001) SUBSTRATES

Three-dimensionally confined GaAs/AlGaAs and InAs/GaAs structures on [ 100] oriented square mesas patterned onto GaAs(001) substrates are rea lized, in-situ, via size-reducing molecular beam epitaxy. Two stages o f mesa top pinch-off involving similar to {103} and subsequently {101} side facets are revealed. GaAs and InAs quantum boxes with lateral li near dimensions down to 40 nm and confined by AlGaAs and GaAs, respect ively, are reported. For InAs, the strain relief in mesas is found to enhance the well known similar to 2 ML thickness for three-dimensional island formation on unpatterned substrates to, remarkably, > 5 ML for mesa size similar to 75 nm. Cathodoluminescence emission from the InA s on the mesa top attests to its good optical quality.