Analysis of crystal structure of epitaxial nanoheterostructures with multiple pseudomorphic quantum wells {In<sub>х</sub>Ga<sub>1</sub><sub>–х</sub>As/GaAs} on GaAs (

The crystal structure of {In0.1Ga0.9As/GaAs} × 10 and {In0.2Ga0.8As/GaAs} × 10 epitaxial multilayer films on GaAs substrates with different orientations has been studied (100), (110), (111)A in order to identify features that may be related to the previously discovered increased efficiency of terahertz radiation generation in films with orientations (110) and (111)A. Significant concentrations of twins and package defects were found in films on non-standard GaAs (110) and (111)A substrates. The composition and thicknesses of individual layers of heterostructures on GaAs (100) substrates have been refined by analyzing thickness fluctuations on diffraction reflection curves.