X-RAY REFLECTIVITY STUDY OF SEMICONDUCTOR INTERFACES

The results of an X-ray reflectivity study of thick AlAs-AlGaAs and th in GeSi-Ge multilayers grown using metal-organic vapour-phase epitaxy and ion-beam sputtering deposition techniques, respectively, are prese nted. Asymmetry in interfaces is observed in both of these semiconduct or multilayers. It is also observed that although the Si-on-Ge interfa ce is sharp, an Si0.4Ge0.6 alloy is formed at the Ge-on-Si interface. In the case of the III-V semiconductor, the AlAs-on-AlGaAs interface s hows much greater roughness than that observed in the AlGaAs-on-AlAs i nterface. For thin multilayers it is demonstrated that the composition al profile as a function of depth can be obtained directly from the X- ray reflectivity data.