Atomic-scale mapping of local lattice distortions in highly strained coherent islands of InXGa1-XAs/GaAs by high-resolution electron microscopy and image processing

摘要: During the epitaxy of highly strained InXGa1-XAs (x> 0.25) on {100}- oriented GaAs, a two-dimensional (2D)-three-dimensional transition growth mode was observed with formation coherent islands. Deformations at atomic scale were measured by image processing high-resolution electron microscopy {110} projections. Quantitative experimental 2D contour maps epsilon x and z deformations perpendicular parallel respectively to direction heterostructure, are presented. Experimental values compared theoretical calculations according model homogeneous solid in biaxial compression. Indium segregation both directions tentatively inferred.