The dislocation microstructure which was associated with the loss of coherency of (001) CdTe, as grown onto (001) GaAs, was characterized by using high-resolution transmission electron microscopy. The examination of cross-sectional specimens permitted characteristic local variations in the relative orientations of the overgrowth and the substrate to be quantified and related to associated local changes in the form and distribution of the interface dislocation array. In the latter array, the relative proportions of 60º dislocations and Lomer-Cottrell locks were found to be related to the local misorientation between CdTe and GaAs. The extent to which this was indicative of the mode of stress relief during coherency loss was considered. It was also found that such variations in the relative proportions of the various types of dislocation were associated with micro-twin formation. This was significant with regard to the strain relief mechanism.

J.E.Angelo, W.W.Gerberich, W.M.Stobbs, G.Bratina, L.Sorba, A.Franciosi: Philosophical Magazine Letters, 1993, 67[4], 279-85