Grazing Incidence X-Ray Scattering from Surfaces and Interfaces. D.K. Bowen and M. Wormington Bede Scientific Incorporated Englewood, Colorado

Thin films, their surfaces and interfaces are playing an increasing role in modern electronic and mechanical materials. Consistent manufacture requires accurate, consistent and sensitive measurement and characterization both of films down to the nm level and of surfaces with sub-nm roughness. X-ray specular and diffuse scatter methods are able to perform such characterization. Specular relfectivity on its own provides extremely accurate measurements of film thicknesses in the range 1 - 1000 nm, and of surface and interface width to about 0.05 nm, but cannot distinguish between the two components of interface width: roughness and composition or density grading. Diffuse scatter can, however, distinguish these effects and also improve the sensitivity and provide information about both lateral and vertical correlations in a multilayer system. The addition of grazing incidence fluorescence provides extra information about composition variations and additional, redundant information about interface widths. These methods will be reviewed with special emphasis on accurate modelling of the scatter and on experimental tests of the models.