X-RAY TRIPLE-CRYSTAL DIFFRACTOMETRY AND TRANSMISSION ELECTRON-MICROSCOPY CHARACTERIZATION OF DEFECTS IN LATTICE-MISMATCHED EPITAXIAL STRUCTURES

X-ray triple-crystal diffractometry has been applied to heterostructur es with a misfit of lattice parameters in the interfaces. Si1-xGex/Si compositions as well as GaSb layers strongly mismatched to GaAs substr ates have been studied. By use of various scans in both the Bragg and Laue geometries, the data are presented either as two-dimensional maps in the scattering plane or as the intensity distribution along the di ffraction vector. The structural parameters of the layers were determi ned from a detailed analysis of the diffraction patterns. The X-ray di ffractometry results are supported by a transmission electron microsco py study.