Structure of lattice-strained InxGa1-xAs/GaAs layers studied by transmission electron microscopy

Abstract

The defect structures of strained InxGa1-xAs/GaAs quantum wells with 0.28≤x≤1.00, which were grown by molecular beam epitaxy on GaAs (001), have been investigated by transmission electron microscopy. It was found that with increasing thicknesses of the layers a transition occurred from homogeneous lattice strain to a "periodic" inhomogeneous lattice strain. This effect was more pronounced with increasing indium content. For thicker layers, misfit dislocations were created which existed together with the periodic inhomogeneous strain. For even thicker layers, dislocation complexes arose which primarily consisted of intersecting stacking faults.