Thomas E. Tiwald

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Phase and microstructure investigations of boron nitride thin films by spectroscopic ellipsometry in the visible and infrared spectral range" (1997). Faculty Publications from the Department of Electrical and Computer Engineering. 64. Spectroscopic ellipsometry over the spectral range from 700 to 3000 cm Ϫ1 and from 1.5 to 3.5 eV is used to simultaneously(More)
In situ infrared and visible-light ellipsometric investigations of boron nitride thin films at elevated temperatures situ infrared and visible-light ellipsometric investigations of boron nitride thin films at elevated temperatures" (1998). Faculty Publications from the Department of Electrical and Computer Engineering. 14. In situ infrared ͑IR͒ spectroscopy(More)
Analysis techniques are needed to determine the quantity and structure of materials composing an organic layer that is below an ultra-thin film limit and in a liquid environment. Neither optical nor acoustical techniques can independently distinguish between thickness and porosity of ultra-thin films due to parameter correlation. A combined optical and(More)
Analytic expressions for the eigenvalues for the four-wave components at an oblique angle of light incidence inside a randomly oriented anisotropic magneto-optic dielectric medium are reported explicitly. In particular, these solutions are valid as long as the dielectric function tensor consists of a symmetric and an antisymmetric part. The normalized Jones(More)
Spectroscopic ellipsometry ͑SE͒ is a noncontact and nondestructive optical technique for thin film characterization. In the past 10 yr, it has migrated from the research laboratory into the semiconductor, data storage, display, communication, and optical coating industries. The wide acceptance of SE is a result of its flexibility to measure most material(More)
concentration and lattice absorption in bulk and epitaxial silicon carbide determined using infrared ellipsometry" We have measured the dielectric function of bulk nitrogen-doped 4H and 6H SiC substrates from 700 to 4000 cm Ϫ1 using Fourier-transform infrared spectroscopic ellipsometry. Photon absorption by transverse optical phonons produces a strong(More)
constants of crystalline WO 3 deposited by magnetron sputtering" (1999). Crystalline WO 3Ϫx is an infrared ͑IR͒ electrochromic material having possible applications in satellite thermal control and IR switches. Optical constants of electrochromic materials change upon ion intercalation, usually with H ϩ or Li ϩ. Of primary concern for device design are the(More)
Thickness analysis of silicon membranes for stencil masks" (2000). Stencil masks are key to charged particle projection lithography, in particular for ion projection lithography. To fulfill pattern printing requirements in the sub-70 nm regime, excellent thickness uniformity and thermal emissivity control are critical parameters for high quality stencil(More)
Optical determination of shallow carrier profiles using Fourier transform infrared ellipsometry" (1998). Faculty Publications from the Department of Electrical and Computer Engineering. 23. Dopant profiles were determined by ex situ Fourier transform infrared variable-angle spectroscopic ellipsometry. The technique exploits carrier absorption in the(More)
Spectroscopic ellipsometry over the spectral range from 700 to 3000 cm Ϫ1 and from 1.5 to 3.5 eV is used to simultaneously determine phase and microstructure of polycrystalline hexagonal and cubic boron nitride thin films deposited by magnetron sputtering on ͑100͒ silicon. The results are obtained from a single microstructure-dependent model for both(More)