CHARACTERIZATION OF GA1-XALXAS/GAAS SUPERLATTICES AND THIN SINGLE LAYERS BY X-RAY-DIFFRACTION

The optimization of the production conditions of laser materials on the basis of multiquantum structures as an active layer requires knowledge of the geometrical structure, chemical composition, and stress profile of the applied superlattice. These data can be established by X-ray diffraction since the periodic hyperstructure of the superlattice in the nanometer region has a detectable influence on the X-ray diffraction pattern. The characterization of superlattices by this technique is performed by an X-ray collimator. In principle it represents a double crystal diffractometer with a slit monolithic Si crystal which is an almost ideal collimator and monochromator. A theoretical consideration is given of the superlattice diffraction. Experimental results of X-ray diffraction measurements are presented.