TEM characterization of La/B4C multilayer systems by the geometric phase method

New La/B4C multilayer systems with layer thicknesses in the nanometer range have been deposited onto structured silicon (001) surfaces by magnetron sputtering and have been characterized by transmission electron microscopy (TEM). By applying a geometric phase method which has been originally developed for measuring displacement fields from high-resolution TEM images, we demonstrate that the structural perfection of multilayers, especially their local layer periods and local layer orientations, can be analyzed with high sensitivity from bright-field TEM images of cross-section specimens. The determination of these structure parameters is relevant for the assessment of the reflectivity properties of such multilayer systems in advanced X-ray optical components.