LACBED measurement of the chemical composition of a thin InxGa1−x As layer buried in a GaAs matrix

Large angle convergent beam electron diffraction (LACBED) observations are used to determine the x indium content of a thin InxGa1−xAs quantum well buried in a GaAs matrix. The method consists in a quantitative analysis of the Bragg line intensities lying in the central disc of any LACBED pattern. This analysis makes it possible to determine the displacement vector R introduced, between the two parts of the GaAs matrix, by the deformation of the quantum well and consequently to determine the x indium content. This indium content is found to be consistent with the value expected from the molecular beam epitaxy growth conditions.