Local Stress in Highly Strained Coherent InGaAs Islands

The 2D-3D transition of the growth mode of highly strained In x Ga 1-x As layers on {100} GaAs was observed by HREM. Local deformations were measured by image processing of HREM {110} projections. e x and e z deformation mappings of In x Ga 1-x As islands are shown. By comparing with theoretical calculation for a homogeneous solid, local indium segregation is expected towards the top of the island. The stress distribution between islands was studied during the growth up to plastic deformation.