DETERMINATION OF THE LAYER STRUCTURE OF EMBEDDED STRAINED INGAAS MULTIPLE-QUANTUM WELLS BY HIGH-RESOLUTION X-RAY-DIFFRACTION

High resolution x-ray diffraction (HRXRD) has been used to determine t he layer compositions and thicknesses of compressively strained InGaAs multiple-quantum-well (MQW) structures embedded in thick cladding lay ers that are nominally lattice matched to InP. The entire layer struct ure was accurately determined from the results of HRXRD measurements f or a simple strained MQW structure in which barriers and claddings are of the same composition. The estimated margins of error are less than 1 % for the quantum-well indium composition and +/-2.5 angstrom for w ell and barrier thicknesses. The layer structure of the active region in a complete InGaAlAs graded-index separate confinement strained MQW laser diode has also been determined by HRXRD.