Effect of misfit dislocations on the Bragg X-ray diffraction from heterostructures

Character of X-ray Bragg diffraction in GaSb and InP-base epitaxial structures with misfit dislocations and without them is investigated by means of three-crystal spectrometer. Dislocation grids are shown to cause the broadening of the diffraction pattern within the reciprocal space in the direction perpendicular to the vector of H reciprocal lattice. It results from scattering character, that shift fields of dislocation grids propagate abnormally far to both film surface and inside the substrate. Different type of three-crystal curves for systems with misfit dislocations and without them allows to determine the presence of dislocation grids within crystal. Plotting the intensity distribution along H vector enables to eliminate the effect of misfit dislocations and to increase reflex resolution from the film and the substrate