NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

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: John S. Villarrubia (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 110

Large Area Real-Space Crystallography and Thickness Determination of Mesoscopic Semiconductor Membranes Using Zone Axis Patterns, Cold Field-Emission SEM/STEM, and Analytical S/TEM

July 25, 2025
Author(s)
Vladimir Oleshko, Glenn Holland, Daron Westly, John Villarrubia
Structural and dimensional characterization of layered structures in semiconductors is increasingly important for microelectronics manufacturing because of the continuing downward scaling of devices. Manufacturers require high-precision non-destructive

Multi-technique reference measurement of critical dimension and shape for model validation in scanning electron microscopy

April 22, 2025
Author(s)
Wataru Yamane, Daron Westly, Glenn Holland, Yu Yamazawa, Naoto Ito, Andras Vladar, John Villarrubia
In semiconductor device manufacturing, 3D structure measurements of newly complex devices would be valuable alongside conventional scanning electron microscopy (SEM) and critical dimension SEM (CD-SEM) measurements. Since these applications in SEM directly

A method to calibrate angular positioning errors using a laser tracker and a plane mirror

March 20, 2025
Author(s)
Balasubramanian Muralikrishnan, Katharine Shilling, Vincent Lee, Olga Ridzel, Glenn Holland, John Villarrubia
We describe a method to calibrate angular positioning errors of a rotation stage using a laser tracker (LT), a plane mirror mounted on the stage, and stationary registration nests placed around the stage. Our technique involves determining the direction of

Model Validation for Scanning Electron Microscopy

April 27, 2023
Author(s)
Olga Ridzel, Wataru Yamane, Ishiaka Mansaray, John S. Villarrubia
We are beginning projects to validate the physics models used for interpretation of electron microscopy images. In one, we will measure electron yields and energy spectra from cleaned well-characterized samples subjected to electron bombardment inside of a

Measuring Tip Shape for Instrumented Indentation Using Atomic Force Microscopy

October 12, 2021
Author(s)
Mark R. VanLandingham, John S. Villarrubia, R M. Camara
Atomic Force Microscopy (AFM) was used to determine the three-dimensional shape of probe tips used for instrumented indentation. AFM images were taken for three probe tips with several different image sizes. The geometry obtained directly from the images

Probing Electrified Liquid-Solid Interfaces with Scanning Electron Microscopy

December 2, 2020
Author(s)
Hongxuan Guo, Alexander Yulaev, Evgheni Strelcov, Alexander Tselev, Christopher M. Arble, Andras Vladar, John S. Villarrubia, Andrei Kolmakov
The mean free path of secondary electrons in aqueous solutions is on the order of a nanometer, making them a suitable probe of ultrathin electrical double layers at solid-liquid electrolyte interfaces. Employing graphene as an electron-transparent

On Low-Energy Tail Distortions in the Detector Response Function of X-Ray Microcalorimeter Spectrometers

November 21, 2019
Author(s)
Galen C. O'Neil, Paul Szypryt, Endre Takacs, Joseph N. Tan, Sean W. Buechele, Aung Naing, Young I. Joe, Daniel S. Swetz, Daniel R. Schmidt, William B. Doriese, Johnathon D. Gard, Carl D. Reintsema, Joel N. Ullom, John S. Villarrubia, Yuri Ralchenko
We use narrow spectral lines from the X-ray spectra of various highly charged ions to measure low-energy tail-like deviations from a Gaussian response function in a microcalorimeter X-ray spectrometer with Au absorbers at energies from 650 to 3320 eV. We

Research Update: Electron beam-based metrology after CMOS

July 19, 2018
Author(s)
James A. Liddle, Brian D. Hoskins, Andras Vladar, John S. Villarrubia
The strengths of and challenges facing electron-based metrology for post-CMOS technology are reviewed. Directed self-assembly, nanophotonics/plasmonics, and resistive switches and selectors, are examined as exemplars of important post-CMOS technologies

3D Nanometrology Based on SEM Stereophotogrammetry

September 18, 2017
Author(s)
Vipin N. Tondare, John S. Villarrubia, Andras Vladar
Three-dimensional (3D) reconstruction of a sample surface from scanning electron microscope (SEM) images taken at two perspectives has been known for decades. However, this method has not been widely used in the semiconductor industry for 3D measurements

Uncertainties in Nanometer-Scale Dimensional Metrology

July 1, 2016
Author(s)
John S. Villarrubia
These are slides used for an oral presentation made at the NIST "Workshop on Quantification of Uncertainties in Material Science." In nanometer-scale dimensional metrology, correction of probing errors, which are caused by the characteristic left/right

Virtual rough samples to test 3D nanometer-scale SEM stereo photogrammetry

March 22, 2016
Author(s)
John S. Villarrubia, Vipin N. Tondare, Andras Vladar
The combination of SEM for high spatial resolution, images from multiple angles to provide 3D information, and commercially available stereo photogrammetry software for 3D reconstruction offers promise for dimensional metrology in 3D. A method is described

Optimizing Hybrid Metrology: Rigorous Implementation of Bayesian and Combined Regression.

November 12, 2015
Author(s)
Mark Alexander Henn, Richard M. Silver, John S. Villarrubia, Nien F. Zhang, Hui Zhou, Bryan M. Barnes, Andras Vladar, Bin Ming
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

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

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

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
Was this page helpful?