In this paper we review various improvements that we made in the development of multilayer mirror optics for home-lab x-ray analytical equipment in recent years. For the detection of light elements using x-ray fluorescence spectrometry, we developed a number of new multilayers with improved detection limits. In detail, we found that La/B4C multilayers improve the detection limit of boron by 29 % compared to the previous Mo/B4C multilayers. For the detection of carbon, TiO2/C multilayers improve the detection limit also by 29 % compared to the V/C multilayers previously used. For the detection of aluminum, WSi2/Si or Ta/Si multilayers can lead to detection limit improvements over the current W/Si multilayers of up to 60 % for samples on silicon wafers. For the use as beam-conditioning elements in x-ray diffractometry, curved optics coated with laterally d-spacing graded multilayers give rise to major improvements concerning usable x-ray intensity and beam quality. Recent developments lead to a high quality of these multilayer optics concerning beam intensity, divergence, beam uniformity and spectral purity. For example, x-ray reflectometry instruments equipped with such multilayer optics have dynamic ranges previously only available at synchrotron sources. Two-dimensional focusing multilayer optics are shown to become essential optical elements in protein crystallography and structural proteomics.

Vakuum in Forschung und PraxisVolume 13, Issue 4 p. 222-231 Article Nanometer-Multischichtsysteme für die Röntgenanalytik Multilayer systems for X-ray analysisi R. Dietsch, R. Dietsch Fraunhofer Institut Werkstoff- und Strahltechnik, Winterbergstraße28, D-01277 Dresden, http://www.iws.fhg.deSearch for more papers by this authorTh. Holz, Th. Holz Fraunhofer Institut Werkstoff- und Strahltechnik, Winterbergstraße28, D-01277 Dresden, http://www.iws.fhg.deSearch for more papers by this authorA. Leson, A. Leson Fraunhofer Institut Werkstoff- und Strahltechnik, Winterbergstraße28, D-01277 Dresden, http://www.iws.fhg.deSearch for more papers by this authorH. Mai, H. Mai Fraunhofer Institut Werkstoff- und Strahltechnik, Winterbergstraße28, D-01277 Dresden, http://www.iws.fhg.deSearch for more papers by this authorD. Bahr, D. Bahr BRUKER AXS GmbH, Östliche Rheinbrückenstraße 50, D-76187 KarlsruheSearch for more papers by this authorL. Brügemann, L. Brügemann BRUKER AXS GmbH, Östliche Rheinbrückenstraße 50, D-76187 KarlsruheSearch for more papers by this authorJ. Lange, J. Lange BRUKER AXS GmbH, Östliche Rheinbrückenstraße 50, D-76187 KarlsruheSearch for more papers by this authorA. Hoffmann, A. Hoffmann PINK GmbH Vakuumtechnik, Am Kessler 06, D-97877 WertheimSearch for more papers by this authorF. Pink, F. Pink PINK GmbH Vakuumtechnik, Am Kessler 06, D-97877 WertheimSearch for more papers by this author R. Dietsch, R. Dietsch Fraunhofer Institut Werkstoff- und Strahltechnik, Winterbergstraße28, D-01277 Dresden, http://www.iws.fhg.deSearch for more papers by this authorTh. Holz, Th. Holz Fraunhofer Institut Werkstoff- und Strahltechnik, Winterbergstraße28, D-01277 Dresden, http://www.iws.fhg.deSearch for more papers by this authorA. Leson, A. Leson Fraunhofer Institut Werkstoff- und Strahltechnik, Winterbergstraße28, D-01277 Dresden, http://www.iws.fhg.deSearch for more papers by this authorH. Mai, H. Mai Fraunhofer Institut Werkstoff- und Strahltechnik, Winterbergstraße28, D-01277 Dresden, http://www.iws.fhg.deSearch for more papers by this authorD. Bahr, D. Bahr BRUKER AXS GmbH, Östliche Rheinbrückenstraße 50, D-76187 KarlsruheSearch for more papers by this authorL. Brügemann, L. Brügemann BRUKER AXS GmbH, Östliche Rheinbrückenstraße 50, D-76187 KarlsruheSearch for more papers by this authorJ. Lange, J. Lange BRUKER AXS GmbH, Östliche Rheinbrückenstraße 50, D-76187 KarlsruheSearch for more papers by this authorA. Hoffmann, A. Hoffmann PINK GmbH Vakuumtechnik, Am Kessler 06, D-97877 WertheimSearch for more papers by this authorF. Pink, F. Pink PINK GmbH Vakuumtechnik, Am Kessler 06, D-97877 WertheimSearch for more papers by this author First published: 15 August 2001 https://doi.org/10.1002/1522-2454(200108)13:4<222::AID-VIPR222>3.0.CO;2-JCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Die Abscheidung von Nanometer-Multischichtsystemen auf technisch relevanten Substraten stellt extreme Anforderungen an die jeweilige Beschichtungstechnologie hinsichtlich Präzision, Reproduzierbarkeit und Langzeitstabilität. Speziell für den Einsatz dieser Multischichten als röntgenoptisches Bauelement müssen eine Variation der Einzelschichtdicken im Bereich unterhalb σD = 0,1nm in einem Schichtstapel mit mehr als 150 Einzelschichten und eine Reproduzierbarkeit der mittleren Periodendicke zwischen zwei Abscheidezyklen von Δd ≤ 0,1nm bei der Beschichtung von Substraten mit bis zu 6“Durchmesser mit der jeweiligen Technologie realisiert werden. Zur Abscheidung solcher röntgenoptischer Nanometer-Multischichten haben sich die Magnetron-Sputtertechnik und die Elektronenstrahlverdampfung etabliert. Sowohl für spezielle Materialkombinationen als auch zur Erzielung vorgegebener Schichtdickenprofile stellt das Verfahren der Puls Laser Deposition (PLD) eine interessante Alternative zu den dominierenden Technologien dar. Dazu wurde im Fraunhofer-IWS Dresden eine spezielle PLD-Konfiguration zur Großflächenabscheidung von Nanometer-Multischichten für röntgenoptische Anwendungen entwickelt. Das Verfahren erzeugt durch Ablation auf der Mantelfläche zylinderförmiger Targets eine definierte Relativbewegung zwischen Plasmafackel und Substrat. Damit können Multischichtsysteme mit homogener Schichtdickenverteilung oder mit vorgegebenen Schichtdickengradienten in einem automatisierten Prozess abgeschieden werden. Diese Großflächentechnologie wurde zur Abscheidung von Metall/Kohlenstoff- und Kohlenstoff/Kohlenstoff- Nanometer-Multischichten für röntgenoptische Anwendungen entwickelt und auf die Beschichtung von Substraten bis 6“Durchmesser aufskaliert. Im Ergebnis der Aufskalierung dieser Technologie können Röntgenspiegel, bestehend aus Kohlenstoff- und Metallabsorbern (z.B. Ni, W, Mo) in Kombination mit geeigneten Spacermaterialien (z.B. C, B4C, Si) mit mehr als 150 Perioden in einem automatisierten Prozess auf Substraten bis 6“Durchmesser abgeschieden werden. Dabei werden unter Verwendung der Großflächen-PLD (LA-PLD) Schichtdickenhomogenitäten besser 1% über 6“ Substratlänge, eine mittlere Abweichung der Einzelschichtdicken im Gesamtstapel von σD ≤ 10pm und eine Reproduzierbarkeit der mittleren Periodendicke zwischen zwei Abscheidezyklen von Δd/d ≈0.6% erreicht. Auf Grund ihrer röntgenoptischen Eigenschaften sind diese Nanometer-Multischichten hervorragend geeignet zur Herstellung röntgenoptischer Komponenten und Baugruppen für die unterschiedlichsten Spektralbereiche. Sie finden als Analysatoren, Monochromatoren und als strahlformende Baugruppen einen zunehmenden Einsatz in der Röntgendiffraktometrie und -reflektometrie, der Röntgenspektroskopie und in der Röntgenastronomie. So können unter Einsatz parabolisch gekrümmter Gradientenmultischichten, den sogenannten Göbel-Spiegeln, in kommerziellen Laborröntgengeräten monochromatische Parallelstrahlbündel für die verschiedensten Wellenlängen (z.B. für Cu Kα-, Mo Kα-, Co Kα-Strahlung) erzeugt werden. Die damit erzielbaren Verbesserungen hinsichtlich z.B. Intensität und einfacher Bedienbarkeit stellen eine neue Qualität in der Röntgenreflektometrie und -diffraktometrie mit Laborröntgenger"ten dar. Citing Literature Volume13, Issue4August 2001Pages 222-231 RelatedInformation

Pulsed Laser Deposition (PLD) has been successfully used for the preparation of multilayers having X-ray optical quality. Outstanding features of the PLD-process are high thickness uniformity, precision of deposition process, formation of smooth interfaces and suppression of columnar growth of thin films. High quality layer stacks with laterally graded thickness distributions across 4“-wafers were used to produce Gobel Mirrors for Mo K α and Cu Kα radiation. Reflectivities up to 90% depending on period thickness and an excellent energy resolution are obtained. The observed FWHM of 1 st BRAGG-orders of typically Δ(2 Θ) ≈ 0.06° (Cu Kα) and Δ(2 Θ) ≈ 0.04° (Mo Kα) requires a very precise shaping of the parabolical mirror to achieve a homogeneous intensity profile of the parallel beam. The performance of such PLD-manufactured Gobel Mirrors in a Twin Gobel Mirror (TGM) arrangement (Cu Kα and Mo Kα) is demonstrated by selected measurements characterizing the excellent beam quality. This TGM arrangement consists of two Gobel Mirrors placed in the primary and in the diffracted beam path, resp. For Cu K α radiation the high monochromized intensity of 10 9 cps is combined with low beam divergence (Δφ < 0.02°) and superior suppression of Cu Kβ radiation ( I(Cu Kα1) : I(Cu Kβ) = 10 6 ) to realize a versatile experimental setup for Xray reflectometry. The determination of layer thicknesses can be carried out regardless of sample displacement.

Performance of Ni/C, Ni/B4C, Mo/B4C and W/B4C multilayers in the energy range E > 8 keV is considered by simulation of x-ray reflectivity and resolution of 1st order Bragg reflection at three different photon energies. The results indicate, that Ni/C and Ni/B4C multilayers show highest theoretical reflectivities of R > 80% for Cu K(alpha) - radiation and also above the Mo K-edge (E equals 20.04 keV) at 30 keV. For Mo K(alpha) -radiation a reflectivity of R > 90% can be achieved by the use of Mo/B4C multilayers. For applications, where period thicknesses d < 3 nm and high reflectivities are required W/B4C multilayers can be used. Theoretical values are compared with X-ray reflectometry results, which were executed at 75 period Ni/C, Ni/B4C and Mo/B4C multilayers, fabricated by pulsed laser deposition (PLD) technology on Si substrates. Amorphous or nanocrystalline structures of single layers, smoothest interfaces and high reproducibility of single layer thickness across the entire layer stack are the results of this high precision PLD process.

Periodic multilayers are well known as Bragg reflectors for X- rays. A high reflectivity and a wide reflection width are their outstanding features. However, if multilayers shall be used as reflective coating for X-ray optics, especially for wide acceptance angles, uniform layer thicknesses cause chromatic aberrations. These aberrations can be overcome by laterally graded multilayer optics. Their Bragg angle is matched laterally to the incidence angle so that for all points on the reflector, Bragg reflection is obtained for the same wavelength. Three major types of laterally graded multilayer mirrors ('Gobel Mirrors') are applied in X-ray diffractometry: (1) parabolic, (2) elliptic and (3) planar. In this paper, we give design criteria and formulae for these mirrors. Furthermore, we discuss the requirements on the dimensions and the fabrication process. Two different processes suitable for the fabrication, sputter coating and pulsed laser deposition (PLD), are described. The X-ray optical parameters and their characterization are presented for various mirrors designed for Cu K(alpha) , Mo K(alpha) and Cr K(alpha) radiation. From Ni/C and Ni/B4C multilayers, high-photon-flux monochromators with a Cu K(beta) /K(alpha) intensity ratio of about 1:1000 have been realized. The divergence of the 'parallel' beam reflected from parabolic mirrors is about 0.02 degrees, which is one order of magnitude lower than the divergence of polycapillary optics, monocapillary optics and waveguides. Comparing the photon flux density in a high resolution diffraction setup with and without mirror optics a gain factor of 16 was achieved for parabolic Ni/B4C multilayer mirrors.

The intensity of Bragg reflections depends strongly on the angle of incidence, if a highly collimated beam of X-rays is impinging at grazing incidence on a thin (200-600 AA) polycrystalline antimony layer. In the case of asymmetric grazing incidence diffraction (AGID) the angle of incidence is small, as the exit angle must be large and nearly twice the Bragg angle. The experimental data are analysed on the basis of the distorted wave Born approximation (DWBA), which yields the thickness d and the optical constants delta and beta of the layer. These parameters are compared with those determined from total external reflection data.

AbstractLately available X-ray optics and 4-axis sample cradles increased the versatility of the Siemens D5000 diffractometer to high resolution applications. The possibilities of the D5000 HR hardware setup are illustrated by presenting diffraction measurements on systems relevant to semiconductor and thin film technology. Well known theoretical approaches are used for the software supported interpretation of the data.

The object of this study is the resolution of a three-crystal diffractometer (TCD) using perfect crystals as monochromator and analyser. It relates to the resolution as a function of the scattering vector Q. This information is crucial for the interpretation of high-resolution X-ray diffraction data obtained very close to reciprocal-lattice points. In this light we present the experimentally determined resolution of TCDs using silicon 111 as well as germanium 111 and 311 reflections, respectively. The values are compared with calculations based on recently published models.

MBE grown gallium arsenide crystals with (001) orientation were investigated with a three-crystal X-ray diffractometer under UHV conditions. In the region of total external reflection (Q<0.3AA-1) no Kiessig fringes occur and hence no electron density difference between the substrate and the MBE layer exists. In the tails of the 004 Bragg reflection, modulations are observed. They are ascribed to a phase shift at the substrate-layer interface originating from a misfit parallel to the surface normal or a thin intermediate layer. The method can be applied to other thin film systems like oxidized or buried layers.

Gallium arsenide crystals with orientations [1\ifmmode\bar\else\textasciimacron\fi{} 1\ifmmode\bar\else\textasciimacron\fi{} 1\ifmmode\bar\else\textasciimacron\fi{}] and [111] were measured with use of a three-crystal x-ray diffractometer. Owing to the preparation of the surface of the substrates and the growing conditions using molecular-beam epitaxy (MBE), a concentration of large defect clusters of several parts per million in the MBE-grown layers results. These defects cause considerable diffuse scattering, which is visible around the reciprocal-lattice points. Even for evaporated MBE layers with thicknesses of only about 3000 \AA{}, diffusely scattered intensity can be detected.

Measurements on evaporated single layers and multilayers of silicon and germanium were carried out using a triple-crystal x-ray diffractometer with perfect Si(111) crystals as a monochromator and analyser. The very high resolution of the triple-crystal diffractometer allows a precise determination of the structural and optical parameters of the layers. The parameters were obtained by fitting a modified Parratt model to the experimental data.