Dresden 2011 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 12: Postersitzung I
MM 12.48: Poster
Monday, March 14, 2011, 17:30–19:00, P5
A Method to Locally Determine Layer Dimensions and Interface Roughness for Multilayer Coatings with Ultimate Accuracy — •Dietrich Häußler1, Ulrich Roß1, Uwe Heidorn2, Frank Hertlein2, Jörg Wiesmann2, and Wolfgang Jäger1 — 1Microanalysis of Materials, Christian-Albrechts-University of Kiel, 24143 Kiel, Germany — 2Incoatec GmbH, 21502 Geesthacht, Germany
Multilayer coatings consisting of ultrathin bilayers on the nanometer scale are essential components of X-ray optics for advanced X-ray analytical equipment and for synchrotron beamlines. Their functionality is based on X-ray scattering from alternating amorphous layers of materials with differing atomic number Z. The development of those layer systems requires precise monitoring of layer thickness, layer periodicity and uniformity, and of interface quality on different length scales. We describe a method for locally determining layer dimensions and interface roughness of multilayer coatings with ultimate accuracy from intensity profiles obtained from high-angle annular dark-field (HAADF) scanning TEM investigations of multilayer cross-sections. Our procedure allows to obtain separate values for lateral interface roughness and interface broadening. For examples of specially designed W-C multilayer systems it is shown that the layer dimensions can be determined with sub-nanometer precision. Comparisons with spatially averaged data obtained from X-ray reflectivity measurements are in satisfactory agreement with our determination of roughness and layer dimensions. The method fails for heavily disturbed multilayer regions involving growth-induced thickness fluctuations.