Ultrathin epitaxial InAs layer relaxation on cross-hatch stress fields

Abstract

Thin, highly-strained InAs layers epitaxially grown on GaAs/InGaAs cross-hatch surfaces undergo postgrowth transformations that yield several morphologies ranging from aligned quantum wires to quantum dots and micron-scale pyramids. The shape varieties result from the multiple pathways created from the combined/competitive effects of asymmetric adatom diffusions, subsurface stress fields and misfit energy minimization. These morphologies reveal the multiple outcomes of metastable states between the two- and the three-dimensional transition that if properly captured and engineered may open up new windows of opportunities both in devices such as sensors and in fundamental quantum studies.