Recent Developments in the X-Ray Reflectivity Analysis for Rough Surfaces and Interfaces of Multilayered Thin Film Materials

Abstract EN

X-ray reflectometry is a powerful tool for investigations on rough surface and interface structures of multilayered thin film materials.

The X-ray reflectivity has been calculated based on the Parratt formalism, accounting for the effect of roughness by the theory of Nevot-Croce conventionally.

However, in previous studies, the calculations of the X-ray reflectivity often show a strange effect where interference effects would increase at a rough surface.

And estimated surface and interface roughnesses from the X-ray reflectivity measurements did not correspond to the TEM image observation results.

The strange result had its origin in a used equation due to a serious mistake in which the Fresnel transmission coefficient in the reflectivity equation is increased at a rough interface because of a lack of consideration of diffuse scattering.

In this review, a new accurate formalism that corrects this mistake is presented.

The new accurate formalism derives an accurate analysis of the X-ray reflectivity from a multilayer surface of thin film materials, taking into account the effect of roughness-induced diffuse scattering.

The calculated reflectivity by this accurate reflectivity equation should enable the structure of buried interfaces to be analyzed more accurately.