Interface dilution and morphology of CdTe/MnTe superlattices studied by small angle x-ray scattering

We have performed small angle X-ray reflectivity measurements on CdTe/MnTe superlattices. The Fresnel optical method and the distorted wave Born approximation were used to extract results from the data. The reflectivity shows that the interface roughness (about 7 Angstrom) is quite large for (43 ML CdTe/8 ML MnTe) and (34 ML CdTe/16 ML MnTe) samples. The effective MnTe concentration is determined from the refractive index. A model of correlated interface profiles is successfully used to simulate the diffuse scattering, and to determine the lateral correlation length of the roughness (Lambda(parallel to) = 1500 +/- 750 Angstrom]; moreover, we demonstrate that the layers are almost completely correlated over the sample thickness in the growth direction. (C) 1998 Elsevier Science B.V. All rights reserved.