HIGH-RESOLUTION X-RAY-DIFFRACTION INVESTIGATION OF CRYSTAL PERFECTIONAND RELAXATION OF GAAS INGAAS/GAAS QUANTUM-WELLS DEPENDING ON MOVPE GROWTH-CONDITIONS/

The influence of growth conditions and the concentration of indium in the vapour phase on the crystal perfection of strained InGaAs/GaAs qua ntum wells grown by metalorganic vapour phase epitaxy is studied by hi gh-resolution X-ray diffraction, cathodoluminescence, photoluminescenc e and transmission electron microscopy. A strong dependence of the mis fit dislocation density on the growth temperature is found. With incre asing In concentration in the vapour phase a transition to the 3-dimen sional growth mode leading to a different type of defect formation is observed.