A FAST X-RAY-METHOD TO DETERMINE GE CONTENT AND RELAXATION OF PARTLY RELAXED SI1-XGEX LAYERS ON SILICON SUBSTRATES

A fast X-ray method is presented to determine the Ge content and the relaxation of partly relaxed SiGe layers on Si substrates using a conventional powder diffractometer. The lattice parameters of the layer parallel and normal to the (001) substrate surface are obtained by a usual omega-20 scan with symmetrical 004 reflection and an omega scan in asymmetrical reflection to measure the relative misorientation between inclined net planes of substrate and layer. The accuracy of this method is checked at a sample with pseudomorphic SiGe layer and its application is demonstrated at three partly relaxed samples with medium Ge content.