U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Andras E. Vladar (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 50 of 185

Scanning electron microscope measurement of width and shape of 10 nm patterned lines using a JMONSEL-modeled library

July 1, 2015
Author(s)
John S. Villarrubia, Andras Vladar, Bin Ming, Regis J. Kline, Daniel F. Sunday, Jasmeet Chawla, Scott List
The width and shape of 10 nm to 12 nm wide lithographically patterned SiO2 lines were measured in the scanning electron microscope by fitting the measured intensity vs. position to a physics-based model in which the lines’ widths and shapes are parameters

NIST-TAPPI Workshop on Measurement Needs for Cellulose Nanomaterial

June 23, 2015
Author(s)
Chelsea S. Davis, Robert J. Moon, Sean Ireland, Linda Johnston, Jo Anne Shatkin, Kim Nelson, E. J. Foster, Aaron M. Forster, Michael T. Postek, Andras Vladar, Jeffrey W. Gilman
A one-day workshop focused on the Measurement Needs for Cellulosic Nanomaterials was organized by the National Institute of Standards and Technology and held in conjunction with the 2014 TAPPI International Conference on Nanotechnology for Renewable

Nanometer level sampling and control of a scanning electron microscope

June 2, 2015
Author(s)
Bradley N. Damazo, Andras Vladar, Olivier M. Marie-Rose, John A. Kramar
The National Institute of Standards and Technology (NIST) is developing a specialized, metrology scanning electron microscope (SEM), having a metrology sample stage measured by a 38 picometer resolution, high-bandwidth laser interferometer system. The

Optimizing Hybrid Metrology: Rigorous Implementation of Bayesian and Combined Regression

March 19, 2015
Author(s)
Mark Alexander Henn, Richard M. Silver, Nien F. Zhang, Hui Zhou, Bryan M. Barnes, Bin Ming, Andras Vladar, John S. Villarrubia
Hybrid metrology, e.g. the combination of several measurement techniques to determine critical dimensions, is an important approach to meet the needs of semiconductor industry. A proper use of hybrid metrology may not only yield more reliable estimates for

Effects of wafer noise on the detection of 20 nm defects using optical volumetric inspection

February 11, 2015
Author(s)
Bryan M. Barnes, Francois R. Goasmat, Martin Y. Sohn, Hui Zhou, Andras Vladar, Richard M. Silver
Patterning imperfections in semiconductor device fabrication may either be noncritical [e.g., line edge roughness (LER)] or critical, such as defects that impact manufacturing yield. As the sizes of the pitches and linewidths decrease in lithography

New Insights into Subsurface Imaging of Carbon Nanotubes in Polymer Composites via Scanning Electron Microscopy

February 4, 2015
Author(s)
Minhua Zhao, Bin Ming, Jae-Woo Kim, Luke J. Gibbons, Xiaohong Gu, Tinh Nguyen, Cheol Park, Peter T. Lillehei, John S. Villarrubia, Andras Vladar, James A. Liddle
Despite many studies of subsurface imaging of carbon nanotube (CNT)-polymer composites via scanning electron microscopy (SEM), significant controversy exists concerning the imaging depth and contrast mechanisms. We studied CNT-polyimide composites and, by

3D Monte Carlo modeling of the SEM: Are there applications to photomask metrology?

October 23, 2014
Author(s)
John S. Villarrubia, Andras Vladar, Michael T. Postek
The ability to model the effect of fields due to charges trapped in insulators with floating conductors has been added to JMONSEL (Java Monte Carlo simulator for Secondary Electrons) and applied to a simple photomask metal on glass geometry. These

Does Your SEM Really Tell the Truth? How Would You Know? Part 2

May 30, 2014
Author(s)
Michael T. Postek, Andras Vladar, Premsagar P. Kavuri
The scanning electron microscope (SEM)has gone through a tremendous evolution to become indispensable for many and diverse scientific and industrial applications. The improvements have significantly enriched and augmented the overall SEM performance and

Optimizing Hybrid Metrology through a Consistent Multi-Tool Parameter Set and Uncertainty Model

April 14, 2014
Author(s)
Richard M. Silver, Bryan Barnes, Nien F. Zhang, Hui Zhou, Andras Vladar, John S. Villarrubia, Regis J. Kline, Daniel Sunday, Alok Vaid
There has been significant interest in hybrid metrology as a novel method for reducing overall measurement uncertainty and optimizing measurement throughput (speed) through rigorous combinations of two or more different measurement techniques into a single

10 nm Three-Dimensional CD-SEM Metrology

April 10, 2014
Author(s)
Andras Vladar, John S. Villarrubia, Bin Ming, Regis J. Kline, Jasmeet Chawla, Scott List, Michael T. Postek
The shape and dimensions of a challenging pattern have been measured using a model-based library scanning electron microscope (MBL SEM) technique. The sample consisted of a 4-line repeating pattern. Lines were narrow (10 nm), asymmetric (different edge

Optical volumetric inspection of sub-20 nm patterned defects with wafer noise

April 2, 2014
Author(s)
Bryan M. Barnes, Francois R. Goasmat, Martin Y. Sohn, Hui Zhou, Richard M. Silver, Andras Vladar, Abraham Arceo
We have previously introduced a new data analysis method that more thoroughly utilizes scattered optical intensity data collected during defect inspection using bright-field microscopy. This volumetric approach allows conversion of focus resolved 2-D

Documentation for Reference Material (RM) 8820: A Versatile, Multipurpose Dimensional Metrology Calibration Standard for Scanned Particle Beam, Scanned Probe and Optical Microscopy

February 3, 2014
Author(s)
Michael T. Postek, Andras Vladar, Bin Ming, Bunday Benjamin
Reference Material (RM) 8820 is a multipurpose instrument calibration standard available from NIST. This is a dimensional standard initially developed to replace the out of stock RM 8090 used for X and Y scale calibrations of scanned particle beam

Does Your SEM Really Tell the Truth? - How would you know? Part 1

December 16, 2013
Author(s)
Michael T. Postek, Andras Vladar
The scanning electron microscope (SEM) has gone through a tremendous evolution to become a critical tool for many and diverse scientific and industrial applications. The high resolution of the SEM is especially suited for both qualitative and quantitative

Does Your SEM Really Tell the Truth? Part 2

November 1, 2013
Author(s)
Michael T. Postek, Andras Vladar, Premsagar P. Kavuri
The scanning electron microscope (SEM) has gone through a tremendous evolution to become indispensable for many and diverse scientific and industrial applications. The first paper in this series, discussed some of the issues related to signal generation in

Three-dimensional deep sub-wavelength defect detection using (lambda) = 193 nm optical microscopy

October 25, 2013
Author(s)
Bryan M. Barnes, Martin Y. Sohn, Francois R. Goasmat, Hui Zhou, Andras Vladar, Richard M. Silver, Abraham Arceo
Identifying defects in photolithographic patterning is a persistent challenge in semiconductor manufacturing. Well-established optical methods in current use are jeopardized by upcoming sub-20 nm device dimensions. Volumetric processing of focus-resolved

Dimensional Metrology and Imaging of Cellulose Nanocrystals

June 14, 2013
Author(s)
Michael T. Postek, Andras Vladar
Cellulose nanocrystals are one group of nanoparticles that have high potential economic value but, also present many basic research and manufacturing challenges. These challenges are not only in development of the fundamental processes needed for the

Does Your SEM Really Tell the Truth?

August 1, 2012
Author(s)
Michael T. Postek, Andras Vladar
The scanning electron microscope (SEM) has gone through a tremendous evolution to become a critical tool for many, diverse scientific and industrial applications. The high resolution of the SEM is especially useful for qualitative and quantitative

Nanoparticle Size and Shape Evaluation Using the TSOM Method

June 1, 2012
Author(s)
Bradley N. Damazo, Ravikiran Attota, Premsagar P. Kavuri, Andras Vladar
A novel through-focus scanning optical microscopy (TSOM) method that yields nanoscale information from optical images obtained at multiple focal planes will be used here for nanoparticle dimensional analysis. The TSOM method can distinguish not only size