The interfacial morphology of strained epitaxial InxGa1−xAs/GaAs

The microstructure of strained layers of InxGa1−xAs/GaAs grown by molecular-beam epitaxy has been investigated by transmission electron microscopy. lt was found that the formation of irregular interfacial morphologies of the InxGa1−xAs layers was due to a transition in growth mode from two-dimensional (layer-by-layer growth) to three-dimensional nucleation via island formation. It was also found that the occurrence of irregular growth surfaces of epitaxial layers was dependent upon inhomogeneous lattice strains induced by the formation of islands. A possible role of lattice strain for the formation of irregular growth surfaces was also discussed.