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Search Publications by: Thomas A. Germer (Fed)

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Displaying 101 - 125 of 385

Generalized ellipsometry of artificially designed line width roughness

December 10, 2010
Author(s)
Martin Foldyna, Thomas A. Germer, Brent Bergner, Ronald G. Dixson
We use azimuthally-resolved spectroscopic Mueller matrix ellipsometry to study a periodic silicon line structure with and without artificially-generated line width roughness (LWR). We model the artificially perturbed grating using 1D and 2D rigorous

Effect of Bandwidth and Numerical Aperture in Optical Scatterometry

March 1, 2010
Author(s)
Thomas A. Germer, Heather J. Patrick
We consider the effects of finite spectral bandwidth and numerical aperture in scatterometry measurements and discuss efficient integration methods based upon Gaussian quadrature in one dimension (for spectral bandwidth averaging) and two dimensions inside

Polarized Optical Scattering Signatures from Biological Materials

January 11, 2010
Author(s)
W. E. Martin, E. Hesse, J. H. Hough, William Sparks, C. S. Cockell, Z. Ulanowski, Thomas Germer, B. Kaye
The polarization of laser light backscattered from biological samples has been measured over the wavelength range 350 to 850nm. Incident circular, linearly polarized, and unpolarized light produces significant spectrally prominent scattered polarizations

A Spectroscopic Polarimeter For Detecting Chiral Signatures In Astrobiological Samples

September 11, 2009
Author(s)
Baoliang Wang, William Sparks, Thomas Germer, Andy Leadbetter
We have developed a polarimeter for accurately measuring both the circular and linear polarization components of a light beam from 400 nm to 800 nm. This polarimeter is designed to work at low light levels that are typical in astronomical applications. It

Developing an Uncertainty Analysis for Optical Scatterometry

August 3, 2009
Author(s)
Thomas A. Germer, Heather J. Patrick, Richard M. Silver, Benjamin Bunday
This article describes how an uncertainty analysis may be performed on a scatterometry measurement. A method is outlined for propagating uncertainties through a least-squares regression. The method includes the propagation of the measurement noise as well

Nanoscale Measurements with a Through-Focus Scanning-Optical-Microscope

July 15, 2009
Author(s)
Ravikiran Attota, Richard M. Silver, Thomas A. Germer
We present a novel optical technique that produces nanometer dimensional measurement sensitivity using a conventional optical microscope, by analyzing through-focus scanning-optical-microscope (TSOM) images obtained at different focus positions. In

Detection of circular polarization in light scattered from photosynthetic microbes

May 12, 2009
Author(s)
William Sparks, James H. Hough, Thomas Germer, Feng Chen, Shiladitya DasSarma, Priya DasSarma, Frank Robb, Nadine Manset, Ludmilla Kolokolova, Neill Reid, F. D. Macchetto, William Martin
The identification of a universal biosignature that could be sensed remotely is critical to the prospects for success in the search for life elsewhere in the universe. A candidate universal biosignature is homochirality, which is likely to be a generic

Effect of Line Width Roughness on Optical Scatterometry Measurements

April 6, 2009
Author(s)
Brent C. Bergner, Thomas Germer, Thomas Suleski
Line width roughness (LWR) has been identified as a potential source of uncertainty in scatterometry measurements, and characterizing its effect is required to improve the method s accuracy and to make measurements traceable. In this work, we extend

Circular Polarization in Scattered Light as a Possible Biomarker

March 2, 2009
Author(s)
Thomas A. Germer, William Sparks, James H. Hough, Ludmilla Kolokolova, Feng Chen, Shiladitya DasSarma, Priya DasSarma, Frank Robb, Nadine Manset, Neill Reid, F. D. Macchetto, William Martin
Biological molecules exhibit homochirality and are optically active. Therefore, it is possible that the scattering of light by biological molecules might result in a macroscopic signature in the form of circular polarization. If this is the case, then

Scatterometry for in situ measurement of pattern reflow in nanoimprinted polymers

December 9, 2008
Author(s)
Heather J. Patrick, Thomas A. Germer, Yifu Ding, Hyun Wook Ro, Lee J. Richter, Christopher L. Soles
We use optical scatterometry to extract the time evolution of the profile of nanoimprinted lines in low and high molecular mass polymer gratings during reflow at the glass transition temperature. The data are obtained continuously during the anneal using a