Abstract

Improving the performance of x-ray multilayer structures hinges on accurate determination and control of the details of interfaces between material pairs. Surface analysis tools, such as RHEED, LEED, Auger, XPS, AFM, and STM, are appropriate for the study of interfaces on a sub-nanometer scale. We have studied the initial stages of growth and interface formation in a variety of material pairs that are used in multilayer x-ray optics. Examples of such single-interface studies will be given, demonstrating the relationship between the growth mode and interface quality. In multilayers, interface roughness may vary throughout the stack and may have a component that is correlated from layer to layer. Specular and non-specular x-ray diffraction measurements and transmission electron microscopy were used to characterize these roughness effects in Mo/Si mirrors for soft x-ray lasers. These data show varying amounts of correlated roughness depending on the sample preparation.

© 1992 Optical Society of America