CHARACTERIZATION OF EPITAXIAL THIN-FILMS BY X-RAY-DIFFRACTION

X-ray diffraction has been used to characterize thin epitaxial films. A new method, grazing-incidence diffraction, with the probing direction parallel to the interface is discussed and applied to several examples. The strain in thin copper films deposited on the basal plane of sapphire was determined in two directions: perpendicular to the interface by symmetric Bragg reflection and parallel to it by grazing-incidence diffraction. Finally, measurements of the lattice strain due to the excitation of electrons from DX centers in heavily tin-doped GaAlAs films on GaAs substrates at low temperature on a triple-crystal diffractometer are presented.