Analysis of surface roughness correlation function by X-ray reflectivity

X-ray reflectivity (XRR) is a powerful tool for the analysis on surface and interface roughness. In the conventional XRR analysis, the reflectivity was calculated based on the Parratt formalism, accounting for the effect of roughness by the theory of Nevot-Croce. We have developed an improved XRR formalism which derives more accurate surface and interface roughness. In this study, we introduced the effective roughness depending on the incidence angle of X-rays. The newly developed XRR formalism, which derives more accurate surface and interface roughness, is found to be dependent on the size of coherent X-rays probing area, and further derives the roughness correlation function as well as the lateral correlation length. Copyright (c) 2016 John Wiley & Sons, Ltd.