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Search Publications by: Thomas A. Germer (Fed)

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Displaying 51 - 75 of 194

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

Modeling the Effect of Finite Size Gratings on Scatterometry Measurements

September 1, 2008
Author(s)
Elizabeth Kenyon, Michael W. Cresswell, Heather Patrick, Thomas Germer
The interpretation of scatterometry measurements generally assumes that the grating extends over an area large enough to intercept all the illumination provided by an incident beam. However, in practice, the gratings used in scatterometry are relatively

Extraction of trench geometry and linewidth of nanoscale grating targets in (110)-oriented silicon using angle-resolved scatterometry

June 9, 2008
Author(s)
Heather J. Patrick, Thomas A. Germer, Michael W. Cresswell, Bin Li, Huai Huang, Paul S. Ho
The extraction of nanoscale dimensions and feature geometry of grating targets using signature-based optical techniques is an area of continued interest in semiconductor manufacturing. In the current work, we have performed angle-resolved scatterometry

Modeling the Effect of Finite Size Gratings on Scatterometry Measurements

February 25, 2008
Author(s)
Elizabeth Kenyon, Michael W. Cresswell, Heather Patrick, Thomas Germer
The interpretation of scatterometry measurements generally assumes that the grating extends over an area large enough to intercept all the illumination provided by an incident beam. However, in practice, the grat-ings used in scatterometry are relatively

Optical Critical Dimension Measurement of Silicon Grating Targets Using Back Focal Plane Scatterfield Microscopy

January 2, 2008
Author(s)
Heather J. Patrick, Ravikiran Attota, Bryan M. Barnes, Thomas A. Germer, Michael T. Stocker, Richard M. Silver, Michael R. Bishop
We demonstrate optical critical dimension measurement of lines in silicon grating targets using back focal plane scatterfield microscopy. In this technique, angle-resolved diffraction signatures are obtained from grating targets by imaging the back focal

Improved Method for Calibrating a Stokes Polarimeter

December 10, 2007
Author(s)
Bruno Boulbry, J C. Ramella-Roman, Thomas A. Germer
We present a method for calibrating polarimeters that uses a set of well-characterized reference polarizations and makes no assumptions about the optics contained in the polarimeter other than their linearity. The method requires that a matrix be

Relaxation Behavior of Polymer Structures Fabricated by Nanoimprint Lithography

August 14, 2007
Author(s)
Yifu Ding, Hyun Wook Ro, Thomas A. Germer, Jack F. Douglas, Brian C. Okerberg, Alamgir Karim, Christopher L. Soles
We study the decay of the imprinted polystyrene (PS) patterns under thermal annealing using light diffraction. The first order diffraction intensity from the imprinted gratings was measured as a function of annealing time. Local intensity maximum is

Modeling and Analysis of Scatterometry Signatures for Optical Critical Dimension Reference Material Applications

May 7, 2007
Author(s)
Heather J. Patrick, Thomas A. Germer, Michael W. Cresswell, Richard A. Allen, Ronald G. Dixson, Michael R. Bishop
We use an optical critical dimension technique, matching modeled to measured scatterometry signatures, to obtain critical dimension linewidth on grating targets fabricated using the single-crystal critical dimension reference materials process. The targets