Improvement of X-Ray Reflectivity Analysis on Surface and Interface Roughness Estimation

摘要

X-ray reflectivity (XRR) is usefull tool to estimate surface and interface roughness. In the conventional XRR analysis, the reflectivity is calculated based on the Parratt formalism, accounting for the effect of roughness by the theory of Nevot-Croce. However, the calculated results have shown often strange behavior due to the fact that the diffuse scattering at the rough interface was not taken into account in the equation. Then we developed new improved formalism to correct this mistake. For deriving more accurate formalism of XRR, we tried to compare the measurements of the surface roughness of the same sample by atomic force microscopy (AFM) and XRR. The results of analysis show that the effective roughness measured by xrrmay depend on the angle of incidence. In this paper, it shows that new improved XRR formalism which derives more accurate surface and interface roughness with depending on the size of the probing area of coherent X-rays.