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Search Publications by: Ndubuisi George Orji (Fed)

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Displaying 26 - 50 of 77

Robust Auto-Alignment Technique for Orientation-Dependent Etching of Nanostructures

May 29, 2012
Author(s)
Craig D. McGray, Richard J. Kasica, Ndubuisi G. Orji, Ronald G. Dixson, Michael W. Cresswell, Richard A. Allen, Jon C. Geist
A robust technique is presented for auto-aligning nanostructures to slow-etching crystallographic planes in materials with diamond cubic structure. Lithographic mask patterns are modified from the intended dimensions of the nanostructures to compensate for

Contour Metrology using Critical Dimension Atomic Force Microscopy

April 9, 2012
Author(s)
Ndubuisi G. Orji, Ronald G. Dixson, Andras Vladar, Bin Ming, Michael T. Postek
The critical dimension atomic force microscope (CD-AFM), which is used as a reference instrument in lithography metrology, has been proposed as a supplemental instrument for contour measurement and verification. However, although data from CD-AFM is

On CD-AFM bias related to probe bending

April 9, 2012
Author(s)
Vladimir A. Ukraintsev, Ndubuisi George Orji, Theodore V. Vorburger, Ronald G. Dixson, Joseph Fu, Richard M. Silver
Critical Dimension AFM (CD-AFM) is a widely used reference metrology. To characterize modern semiconductor devices, very small and flexible probes, often 15 nm to 20 nm in diameter, are now frequently used. Several recent publications have reported on

Traceable Calibration of a Critical Dimension Atomic Force Microscope

March 9, 2012
Author(s)
Ronald G. Dixson, Ndubuisi G. Orji, Craig D. McGray, John E. Bonevich, Jon C. Geist
The National Institute of Standards and Technology (NIST) has a multifaceted program in atomic force microscope (AFM) dimensional metrology. One component of this program, and the focus of this paper, is the use of critical dimension atomic force

Traceable Calibration of a Critical Dimension Atomic Force Microscope

June 6, 2011
Author(s)
Ronald G. Dixson, Ndubuisi G. Orji, Craig D. McGray, Jon C. Geist
The National Institute of Standards and Technology (NIST) has a multifaceted program in atomic force microscope (AFM) dimensional metrology. One component of this effort is a custom in-house metrology AFM, called the calibrated AFM (C-AFM). The NIST C-AFM

Progress on CD-AFM tip width calibration standards

May 10, 2011
Author(s)
Ronald G. Dixson, Boon Ping Ng, Craig D. McGray, Ndubuisi G. Orji, Jon C. Geist
The National Institute of Standards and Technology (NIST) is developing a new generation of standards for calibration of CD-AFM tip width. These standards, known as single crystal critical dimension reference materials (SCCDRM) have features with near

Measurement Traceability and Quality Assurance in a Nanomanufacturing Environment

March 8, 2011
Author(s)
Ndubuisi G. Orji, Ronald G. Dixson, Aaron Cordes, Benjamin Bunday, John Allgair
A key requirement for nano-manufacturing is maintaining acceptable traceability of measurements performed to determine size. Given that properties and functionality at the nanoscale are governed by absolute size, maintaining the traceability of dimensional

Scanning Probe Microscope Dimensional Metrology at NIST

December 21, 2010
Author(s)
John A. Kramar, Ronald G. Dixson, Ndubuisi G. Orji
Scanning probe microscopy (SPM) dimensional metrology efforts at the U.S. National Institute of Standards and Technology are reviewed. The main SPM instruments for realizing the International System of Units (SI) are the Molecular Measuring Machine, the

Nano- and Atom-scale Length Metrology

October 1, 2010
Author(s)
Theodore V. Vorburger, Ronald G. Dixson, Ndubuisi G. Orji, Joseph Fu, Richard A. Allen, Michael W. Cresswell, Vincent A. Hackley
Measurements of length at the nano-scale have increasing importance in manufacturing, especially in the electronics and biomedical industries. The properties of linewidth and step height are critical to the function and specification of semiconductor

Interlaboratory Comparison of Traceable Atomic Force Microscope Pitch Measurements

June 14, 2010
Author(s)
Ronald G. Dixson, Donald Chernoff, Shihua Wang, Theodore V. Vorburger, Ndubuisi G. Orji, Siew-Leng Tan, Joseph Fu
The National Institute of Standards and Technology (NIST), Advanced Surface Microscopy (ASM), and the National Metrology Centre (NMC) of the Agency for Science, Technology, and Research (A*STAR) in Singapore have undertaken a three-way interlaboratory

Calibration of 1 nm SiC Step Height Standards

March 31, 2010
Author(s)
Theodore V. Vorburger, Albert M. Hilton, Ronald G. Dixson, Ndubuisi G. Orji, J. A. Powell, A. J. Trunek, P. G. Neudeck, P. B. Abel
We aim to develop and calibrate a set of step height standards to meet the range of steps useful for nanotechnology. Of particular interest to this community is the calibration of atomic force microscopes operating at their highest levels of magnification

Traceability: The Key to Nanomanufacturing

December 30, 2009
Author(s)
Ndubuisi George Orji, Ronald G. Dixson, Bryan Barnes, Richard M. Silver
Over the last few years key advances have been made in the area of nanomanufacturing and nanofabrication. Several researchers have produced nanostructures using either top-down or bottom-up techniques, while other groups have functionalized such structures

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

Measurement Traceability and Quality Assurance in a Nanomanufacturing Environment

September 25, 2009
Author(s)
Ndubuisi G. Orji, Ronald G. Dixson, Aaron Cordes, Benjamin Bunday, John Allgair
A key requirement for nano-manufacturing is maintaining acceptable traceability of measurements performed to determine size. Given that properties and functionality at the nanoscale are governed by absolute size, maintaining the traceability of dimensional

A moving window correlation method to reduce the distortion of SPM images

August 20, 2009
Author(s)
Wei Chu, Joseph Fu, Ronald G. Dixson, Ndubuisi G. Orji, Theodore V. Vorburger
Many scanning probe microscopes (SPMs), such as the scanning tunneling microscope (STM) and atomic force microscope (AFM), use piezoelectric actuators operating in open loop for generating the scans of the surfaces. However, nonlinearities mainly caused by

Reference Metrology in a Research Fab: The NIST Clean Calibrations Thrust

April 12, 2009
Author(s)
Ronald G. Dixson, Ndubuisi G. Orji, Joseph Fu, Thomas B. Renegar, Xiaoyu A. Zheng, Theodore V. Vorburger, Albert M. Hilton, Marc J. Cangemi, Lei Chen, Michael A. Hernandez, Russell E. Hajdaj, Michael R. Bishop, Aaron Cordes
In 2004, the National Institute of Standards and Technology (NIST) commissioned the Advanced Measurement Laboratory (AML) – a state-of-the-art, five-wing laboratory complex for leading edge NIST research. The NIST NanoFab – a 1765 m2 (19,000 ft2) clean

Comparison of Measurement Techniques for Linewidth Metrology on Advanced Photomasks

February 19, 2009
Author(s)
Stewart Smith, Andreas Tsiamis, Martin McCallum, Andrew Hourd, J Stevenson, Anthony Walton, Ronald G. Dixson, Richard A. Allen, James E. Potzick, Michael W. Cresswell, Ndubuisi George Orji
This paper compares electrical, optical, and atomic force microscope (AFM) measurements of critical dimension (CD)made on a chrome on quartz photomask. Test structures suitable for direct, on-mask electrical probing have been measured using the above three

2nd Annual Tri-National Workshop on Standards for Nanotechnology - (NIST presentations)

December 10, 2008
Author(s)
Ronald G. Dixson, Jon R. Pratt, Vincent A. Hackley, James E. Potzick, Richard A. Allen, Ndubuisi G. Orji, Michael T. Postek, Herbert S. Bennett, Theodore V. Vorburger, Jeffrey A. Fagan, Robert L. Watters
A new era of cooperation between North American National Measurement Institutes (NMIs) was ushered by the National Research Council of Canada Institute for National Measurement Standards (NRC-INMS) on February 7, 2007 when the first Tri-National workshop

Accuracy Considerations for Critical Dimension Semiconductor Metrology

September 9, 2008
Author(s)
Ronald G. Dixson, Ndubuisi G. Orji, B Bunday, J Allgair
As the size of integrated circuit features continues to decrease, the accuracy of measurements becomes more important. Due to greater emphasis on precision rather than accuracy, many of the measurements made in semiconductor fabs are not traceable to 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

Towards Accurate Feature Shape Metrology

March 22, 2008
Author(s)
Ndubuisi G. Orji, Ronald G. Dixson, B Bunday, J Allgair
Over the last few years, the need for shape metrology for process control has increased. A key component of shape metrology is sidewall angle (SWA). However, few instruments measure SWA directly. The critical dimension atomic force microscope (CD-AFM) is