Characterization of engineering surfaces by grazing-incidence X-ray reflectivity

This paper covers the principles and practice of grazing-incidence reflectometry and its application to the characterization of surfaces and very thin surface layers of single or polycrystalline materials. It is shown that film thicknesses may be accurately measured in the range from monolayers up to about a micrometre, that roughness parameters from zero to about 2 nm may be deduced, and that the diffuse reflectivity is sensitive to the distribution and correlation length of the surface structure. Applications to semiconductor and magnetic multilayers are demonstrated, and the use of the method for study of interfaces and conformal roughening is considered.