William A. McGahan

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Ellipsometric determination of optical constants for silicon and thermally grown silicon dioxide via a multi-sample, multi-wavelength, multi-angle investigation" (1998). Optical constant spectra for silicon and thermally grown silicon dioxide have been simultaneously determined using variable angle of incidence spectroscopic ellipsometry from 0.75 to 6.5(More)
The use of optical metrology techniques in process control for microelectronic manufacturing has become widespread. These techniques are fast and non-destructive, allowing a higher sampling rate than non-optical methods like scanning electron or atomic force microscopy. One drawback of most optical metrology tools is the requirement that special measurement(More)
Variable angle of incidence spectroscopic ellipsometry (VASE) is commonly used for multilayer optical analysis, but in some cases this experiment (performed in reflection) does not provide sufficient information for the unique determination of the thicknesses and optical constants of the films in the given multilayer. We have found that augmenting the VASE(More)
optic and optical characterization of Tb/Co compositionally modulated amorphous films" (1991). Amorphous Tb/Co compositionally modulated films were deposited on Si substrates with different modulation layer thicknesses ranging from about 2.5 to 15 A. The nominal Tb to Co layer thickness ratios were systematically varied and the complex refractive index (n(More)
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