Compositional nonuniformities and strain relaxation at misoriented InxGa(1−x)As/GaAs interfaces

Abstract

Compositional nonuniforimities and misfit dislocations are observed near misoriented In0.2Ga0.8As/GaAs interfaces. The compositional nonuniformities results from In interdiffusion at the interface over a distance of 3 nm and formation of InAs platelet precipitates. The misfit dislocations are of pure edge and 60° types. The core of pure edge misfit dislocations generally consists of two 60° dislocations separated by approximately 2.5 nm. One of these 60° dislocations is usually split into partials and decorated by platelets of InAs. The interface and surface morphologies are strongly influenced by the substrate tilt away from exact [001] crystallographic orientation.