Determination of layer-thickness fluctuations in Mo/Si multilayers by cross-sectional HR-TEM and X-ray diffraction

Aschentrup A, Hachmann W, Westerwalbesloh T, Lim YC, Kleineberg U, Heinzmann U. Determination of layer-thickness fluctuations in Mo/Si multilayers by cross-sectional HR-TEM and X-ray diffraction. APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING. 2003;77(5):607-611.We present a method of deriving single layer thickness fluctuations of Mo/Si EUV multilayers from cross-sectional high-resolution transmission electron microscopy micrographs. The obtained thickness values for each layer are used in a layer model to calculate the grazing-incidence X-ray reflectivity (GIXRR) and the corresponding at-wavelength-reflectivity curves. Comparison with XRR measurements shows the strong effect of thickness fluctuations on the intensity of the secondary Kiessig fringes and the main Bragg maxima. This model results in substantially better reflectivity simulations than the standard periodic four-layer model or the assumption of statistically distributed (random) thickness errors. Results for reflectivity curves at 13-nm wavelength are discussed in terms of peak reflectivity, peak shift and further changes in the shape of the reflectivity curve

Aperiodic nanometer multilayer systems as optical key components for attosecond electron spectroscopy

Wonisch A, Westerwalbesloh T, Hachmann W, Kabachnik NM, Kleineberg U, Heinzmann U. Aperiodic nanometer multilayer systems as optical key components for attosecond electron spectroscopy. Thin Solid Films 464-465. 2004;464-465:473-477

Effect of substrate roughness on Mo/Si multilayer optics for EUVL produced by UHV-e-beam evaporation and ion polishing

Kleineberg U, Westerwalbesloh T, Hachmann W, et al. Effect of substrate roughness on Mo/Si multilayer optics for EUVL produced by UHV-e-beam evaporation and ion polishing. In: Thin Solid Films. THIN SOLID FILMS. Vol 433. ELSEVIER SCIENCE SA; 2003: 230-236.Our current status of Mo/Si multilayer extreme ultraviolet coatings fabricated by UHV e-beam evaporation and ion polishing is presented. Standard Mo/Si multilayer coating deposited onto 4 inch Si-wafer substrates showing peak reflectivities of 67.4% with a lateral homogeneity in coating reflectance of approximately 0.3% and a variation in peak wavelength of approximately 0.05 nm. over the full aperture have been achieved. At-wavelength reflectivities achieved for comparable multilayer coatings deposited onto Zerodur substrates with an enhanced microroughness (sigma = 0.55 nm) is shown to drop severely by almost 10%. A partial smoothing could be achieved by applying thin a-C buffer layers to these substrates, which in turn enhance the atwavelength reflectivity of the Mo/Si multilayer by 0.7%. (C) 2003 Elsevier Science B.V. All rights reserved

Preparation and characterization of gold nanocrystals on NaCl(100) surfaces as labels for the dynamical x-ray tracking technique

Slieh J, Winter A, Gryzia A, et al. Preparation and characterization of gold nanocrystals on NaCl(100) surfaces as labels for the dynamical x-ray tracking technique. Thin Solid Films. 2009;517(11):3257-3261.We report on the fabrication of single crystalline gold nanocrystals of sizes between 10 nm and 25 nm. Gold was deposited under ultra high vacuum conditions on a freshly-cleaved NaCl(100) surface by means of the Molecular Beam Epitaxy technique. The preparation parameters substrate temperature and average thickness of the deposited gold were studied systematically. After the preparation, the crystals were characterized by means of different techniques, such as Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), X-Ray Diffractometry (XRD) and Laue Diffractometry. Measurements of the deposited cluster size, as measured by AFM, and the crystal size, as measured by XRD exhibited similar results at substrate temperatures between approx. 200 degrees C and 250 degrees C, indicating a high amount of single gold crystals. TEM images of gold crystals, made after the gold crystals had been dissolved in an aqueous 3-[(3-cholamidopropyl)dimethyl-ammonio]propane solution, support these results. Further, an effect of the substrate temperature during the deposition on the orientation of the gold crystals with respect to the NaCl(100) surface was observed. XRD measurements reveal a perpendicular texture of Au (111) parallel to NaCl(001) at approximately 310 degrees C. The second detected texture:Au(001)parallel to NaCl(001) (in plane) and Au[100]parallel to NaCl[100] (perpendicular) was observed over the complete studied temperature range (180 degrees C-330 degrees C). (C) 2008 Elsevier B.V. All rights reserved