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Search Publications by: Michael T. Stocker (Fed)

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Displaying 1 - 25 of 44

Evaluating Measurement Uncertainty for Firearm Barrel and Overall Length Measurements

November 1, 2021
Author(s)
Michael Stocker, Theodore V. Vorburger, Thomas Renegar, Robert Thompson, Mark Williford
In recent years, more forensic laboratories are seeking accreditation to ISO 17020 and 17025. In the field of firearm and toolmark forensics, the barrel length and overall length of a firearm are typical measurements performed in the laboratory to

A Metrology Foundation for 3D Ballistic Imaging - NIJ Final Technical Report

September 1, 2021
Author(s)
Michael Stocker, Johannes Soons, Thomas Renegar, Xiaoyu Zheng, Robert Thompson
Forensic laboratories considering optical 3D surface topography measurement for objective comparison and VCM face challenges with respect to cost, training, and quality assurance. The primary aim of this research was to address quality assurance issues

Addressing Quality Assurance Issues in 3D Firearm and Toolmark Imaging

April 1, 2018
Author(s)
Michael T. Stocker, Robert M. Thompson, Johannes A. Soons, Thomas B. Renegar, Xiaoyu A. Zheng
The emerging capability for measuring and analyzing the three-dimensional (3D) surface topography of forensic samples is expected to have a profound impact on firearm and toolmark identification. As forensic laboratories are working to integrate 3D

Results of an international photomask linewidth comparison of NIST and PTB

October 9, 2009
Author(s)
Bernd Bodermann, Detleff Bergmann, Egbert Buhr, Wolfgang Haebler-Grohne, Harald Bosse, James E. Potzick, Ronald G. Dixson, Richard Quintanilha, Michael T. Stocker, Andras Vladar, Ndubuisi George Orji
In preparation of the international Nano1 linewidth comparison on photomasks between 9 national metrology institutes, NIST and PTB have started a bilateral linewidth comparison in 2008, independent of and prior to the Nano1 comparison in order to test the

Photomask metrology using a 193 nm scatterfield microscope

September 30, 2009
Author(s)
Richard Quintanilha, Bryan M. Barnes, Martin Y. Sohn, Lowell P. Howard, Richard M. Silver, James E. Potzick, Michael T. Stocker
The current photomask linewidth Standard Reference Material (SRM) supplied by the National Institute of Standards and Technology (NIST), SRM 2059, is the fifth generation of such standards for mask metrology. The calibration of this mask has been usually

International photomask linewidth comparison by NIST and PTB

October 17, 2008
Author(s)
James E. Potzick, Ronald G. Dixson, Richard Quintanilha, Michael T. Stocker, Andras Vladar, Egbert Buhr, Bernd Bodermann, Wolfgang Hassler-Grohne, Harald Bosse, C.G. Frase
In preparation of the international Nano1 linewidth comparison on photomasks between 8 national metrology institutes, NIST and PTB have started a bilateral linewidth comparison in 2008, independent of and prior to the Nano1 comparison in order to test the

Through-focus Scanning and Scatterfield Optical Methods for Advanced Overlay Target Analysis

September 1, 2008
Author(s)
Ravikiran Attota, Michael T. Stocker, Richard M. Silver, Nathanael A. Heckert, Hui Zhou, Richard J. Kasica, Lei Chen, Ronald G. Dixson, Ndubuisi G. Orji, Bryan M. Barnes, Peter Lipscomb
In this paper we present overlay measurement techniques that use small overlay targets for advanced semiconductor applications. We employ two different optical methods to measure overlay using modified conventional optical microscope platforms. They are

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

Extending the Limits of Image-Based Optical Metrology

June 20, 2007
Author(s)
Richard M. Silver, Bryan M. Barnes, Ravikiran Attota, Jay S. Jun, Michael T. Stocker, Egon Marx, Heather J. Patrick
We have developed a set of techniques, referred to as scatterfield microscopy, in which the illumination is engineered in combination with appropriately designed metrology targets. Previously we reported results from samples with sub-50 nm sized features

Calibrated Overlay Wafer Standard

January 1, 2007
Author(s)
Michael T. Stocker, Richard M. Silver, Ravikiran Attota, Jay S. Jun
This document describes the physical characteristics of Standard Reference Material SRM 5000, provides guidance for its use in calibrating overlay (OL) tools, and gives information and precautions concerning its care and handling.Standard Reference

Koehler Illumination for High-Resolution Optical Metrology

March 1, 2006
Author(s)
Martin Y. Sohn, Bryan M. Barnes, Lowell P. Howard, Richard M. Silver, Ravikiran Attota, Michael T. Stocker
Accurate preparation of illumination is critical for high-resolution optical metrology applications such as line width and overlay measurements. To improve the detailed evaluation and alignment of the illumination optics, we have separated Koehler

The Limits of Image-Based Optical Metrology

March 1, 2006
Author(s)
Richard M. Silver, Bryan M. Barnes, Ravikiran Attota, Jay S. Jun, James J. Filliben, Juan Soto, Michael T. Stocker, P Lipscomb, Egon Marx, Heather J. Patrick, Ronald G. Dixson, Robert D. Larrabee
An overview of the challenges encountered in imaging device-sized features using optical techniques recently developed in our laboratories is presented in this paper. We have developed a set of techniques we refer to as scatterfield microscopy which allows

High-resolution Optical Metrology

May 1, 2005
Author(s)
Richard M. Silver, Ravikiran Attota, Michael T. Stocker, M R. Bishop, Lowell P. Howard, Thomas A. Germer, Egon Marx, M P. Davidson, Robert D. Larrabee
Recent advances in optical imaging techniques have unveiled new possibilities for optical metrology and optical-based process control measurements of features in the 65 nm node and beyond. In this paper we discuss methods and applications that combine