X-ray diffraction study and quantitative measurements of high dislocation densities in superlattices and single crystal layers of heteroepitaxial systems with pronounced lattice mismatch

1063-7745

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Abstract Plastic deformation in a single-crystal layer of the In0.12Ga0.88As/(111)InP solid solution is identified by the methods of X-ray diffractometry (XRD) and the double-crystal pseudorocking curves (DCPRC). X-ray topographs showed the generation of three intersecting systems of straight dislocations in the layer. In a one-layer ZnSe/GaAs structure and multilayer ZnSe/ZnSe1 − x Sx/ZnSe/GaAs structures, the elastic and plastic strains were detected by the combined XRD-DCPRC method. The major components of the thermoelastic and plastic-deformation tensors were determined as εxx = εyy = 3.5 × 10−3 and εzz = 2.35 × 10−3. Using these data, the dislocation densities were determined as N d ∼ 2.5 × 108 cm−2 and N d ∼ 3 × 1010 cm−2 for the 7 µm-thick ZnSe and 1 µm-thick InAs layers, respectively. In a superlattice of the AlxGa1 − x As/GaAs/⋯/GaAs-type with a large lattice parameter, the plastic deformation was detected. X-ray topography confirmed that the dislocation density in this superlattice equals ∼105 cm−2.

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