Высокоточная характеризация сверхмногопериодных AlGaAs/GaAs-сверхрешеток с помощью рентгеновской рефлектометрии на синхротронном источнике

The morphology of Al0.3Ga0.7As / GaAs superlattices grown by molecular beam epitaxy was determined by X-ray reflectometry (including a synchrotron radiation source) and photoluminescence. The thicknesses of the superlattice layers with 100 periods, found using laboratory and synchrotron studies, correlate with an accuracy of ~ 1%. At the synchrotron, beginning with high (> 4−5) Bragg orders, reflection peaks were found that are not observed in measurements with a diffractometer and are apparently associated with the technological features of the growth of such structures. It follows from the analysis that the peaks correspond to modulation in the superlattice with a period 3–5 times greater and characterize the scatter of the thicknesses over the structure depth by several percent.