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dc.contributor.authorFERNANDEZ, FELIX EUGENIO.
dc.creatorFERNANDEZ, FELIX EUGENIO.en_US
dc.date.accessioned2011-10-31T17:01:59Z
dc.date.available2011-10-31T17:01:59Z
dc.date.issued1987en_US
dc.identifier.urihttp://hdl.handle.net/10150/184211
dc.description.abstractCurrent technology has made possible the fabrication of multilayered optical elements for soft x-ray radiation. These structures find a variety of important applications. Difficulties in the design and fabrication of multilayers for soft x-rays are related to the lack of information about the properties of materials in the very thin layers (~5-100 Å) required. Imperfections cause the measured optical properties of the multilayers to deviate strongly from ideal behavior. Realistic calculations of reflectance must take these imperfections into account. We review the pertinent theory, with attention to the problem of including non-ideal properties. We also review characterization techniques suitable for the measurement of relevant structural and stoichiometric parameters of the multilayer. A detailed characterization procedure is presented. This procedure is capable of accurately determining the layer thicknesses, material densities, interfacial rms roughness or diffusion values, crystalline structure, concentration of contaminants, and extent of surface oxidation. The techniques used included low-angle x-ray θ-2θ diffraction with parallel-beam and Bragg-Brentano geometries, wide-film Debye-Scherrer ("Read") camera and Seemann-Bohlin diffractometer, Rutherford backscattering spectroscopy, and transmission electron microscopy. Si/W multilayer mirrors were designed for normal-incidence 210 Å radiation. Samples were fabricated using a magnetically-confined-plasma dc-triode sputtering technique. Our characterization procedure was applied to these samples. To our knowledge, this is the first time such a comprehensive set of characterization techniques has been applied to a multilayer x-ray optical element. The same samples were tested with synchrotron radiation over a wide spectral range, and for several incidence angles. The measured reflectance is in excellent agreement with curves calculated using the information obtained from the characterization results, with no adjustable parameters. The Si/W combination is shown to have good layering characteristics. The near-normal reflectance of the multilayers was 20 to 30 times better than the reflectivity of the best single-surface mirrors at the same wavelengths.
dc.language.isoenen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectX-ray optics.en_US
dc.subjectThin films, Multilayered.en_US
dc.subjectGrenz rays.en_US
dc.titleMULTILAYER REFLECTORS FOR SOFT X-RAYS.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.identifier.oclc699819530en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.identifier.proquest8727925en_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePh.D.en_US
dc.description.noteThis item was digitized from a paper original and/or a microfilm copy. If you need higher-resolution images for any content in this item, please contact us at repository@u.library.arizona.edu.
dc.description.admin-noteOriginal file replaced with corrected file April 2023.
refterms.dateFOA2018-08-22T16:13:52Z
html.description.abstractCurrent technology has made possible the fabrication of multilayered optical elements for soft x-ray radiation. These structures find a variety of important applications. Difficulties in the design and fabrication of multilayers for soft x-rays are related to the lack of information about the properties of materials in the very thin layers (~5-100 Å) required. Imperfections cause the measured optical properties of the multilayers to deviate strongly from ideal behavior. Realistic calculations of reflectance must take these imperfections into account. We review the pertinent theory, with attention to the problem of including non-ideal properties. We also review characterization techniques suitable for the measurement of relevant structural and stoichiometric parameters of the multilayer. A detailed characterization procedure is presented. This procedure is capable of accurately determining the layer thicknesses, material densities, interfacial rms roughness or diffusion values, crystalline structure, concentration of contaminants, and extent of surface oxidation. The techniques used included low-angle x-ray θ-2θ diffraction with parallel-beam and Bragg-Brentano geometries, wide-film Debye-Scherrer ("Read") camera and Seemann-Bohlin diffractometer, Rutherford backscattering spectroscopy, and transmission electron microscopy. Si/W multilayer mirrors were designed for normal-incidence 210 Å radiation. Samples were fabricated using a magnetically-confined-plasma dc-triode sputtering technique. Our characterization procedure was applied to these samples. To our knowledge, this is the first time such a comprehensive set of characterization techniques has been applied to a multilayer x-ray optical element. The same samples were tested with synchrotron radiation over a wide spectral range, and for several incidence angles. The measured reflectance is in excellent agreement with curves calculated using the information obtained from the characterization results, with no adjustable parameters. The Si/W combination is shown to have good layering characteristics. The near-normal reflectance of the multilayers was 20 to 30 times better than the reflectivity of the best single-surface mirrors at the same wavelengths.


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