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Publications

Search Publications by

Ronald G. Dixson (Fed)

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Displaying 1 - 25 of 137

Sub-picoliter Traceability of Microdroplet Gravimetry and Microscopy

December 20, 2021
Author(s)
Lindsay C. C. Elliott, Adam L. Pintar, Craig R. Copeland, Thomas B. Renegar, Ronald G. Dixson, B. Robert Ilic, R. Michael Verkouteren, Samuel M. Stavis
Volumetric analysis of single microdroplets is difficult to perform by ensemble gravimetry, whereas optical microscopy is often inaccurate beyond the resolution limit. To address the latter issue, we advance and integrate these complementary methods

Wear comparison of critical dimension-atomic force microscopy tips

March 28, 2020
Author(s)
Ndubuisi G. Orji, Ronald G. Dixson, Ernesto Lopez, Bernd Imer
Nanoscale wear affects the performance of atomic force microscopy (AFM)-based measurements for all applications including process control, nanoelectronics characterization and topography measurements. As such, methods to prevent or reduce AFM tip wear is

Spatial Dimensions in Atomic Force Microscopy: Instruments, Effects, and Measurements

August 15, 2018
Author(s)
Ronald G. Dixson, Ndubuisi G. Orji, Ichiko Misumi, Gaoliang Dai
Atomic force microscopes (AFMs) are commonly and broadly regarded as being capable of three dimensional imaging. However, conventional AFMs suffer from both significant functional constraints and imaging artifacts that render them less than fully three

Contour Metrology using Critical Dimension Atomic Force Microscopy

December 15, 2016
Author(s)
Ndubuisi G. Orji, Ronald G. Dixson, Boon Ping Ng, Andras Vladar, Michael T. Postek
The critical dimension atomic force microscope (CD-AFM) has been proposed as an instrument for contour measurement and verification – since its capabilities are complementary to the widely used scanning electron microscope (SEM). Although data from CD-AFM

Transmission Electron Microscope Calibration Methods for Critical Dimension Standards

October 13, 2016
Author(s)
Ndubuisi G. Orji, Ronald G. Dixson, Domingo I. Garcia-Gutierrez, Bunday Benjamin, M R. Bishop, Michael W. Cresswell, Richard A. Allen, John Allgair
One of the key challenges in critical dimension (CD) metrology is finding suitable dimensional calibration standards. The transmission electron microscope (TEM), which produces lattice-resolved images having scale traceability to the SI (International

Evaluation of Carbon Nanotube Probes in Critical Dimension Atomic Force Microscopes

August 26, 2016
Author(s)
Jinho Choi, Byong Chon Park, Sang Jung Ahn, Dal-Hyun Kim, J Lyou, Ronald G. Dixson, Ndubuisi George Orji, Joseph Fu, Theodore V. Vorburger
The decreasing size of semiconductor features and the increasing structural complexity of advanced devices has placed continuously greater demands on manufacturing metrology-arising both from the measurement challenges of smaller feature sizes and the

Process Optimization for Lattice-Selective Wet Etching of Crystalline Silicon Structures

March 9, 2016
Author(s)
Ronald G. Dixson, William F. Guthrie, Richard A. Allen, Ndubuisi G. Orji, Michael W. Cresswell, Christine E. Murabito
Lattice-selective etching of silicon is used in a number of applications, but it is particularly valuable in those for which the lattice-defined sidewall angle can be beneficial to the functional goals. A relatively small but important niche application is

Lateral Tip Control Effects in CD-AFM Metrology: The Large Tip Limit

January 25, 2016
Author(s)
Ronald G. Dixson, Ndubuisi G. Orji, Ryan Goldband
Sidewall sensing in CD-AFMs usually involves continuous lateral dithering of the tip or the use of a control algorithm and fast response piezo actuator to position the tip in a manner that resembles touch-triggering of coordinate measuring machine (CMM)

Tip characterization method using multi-feature characterizer for CD-AFM

December 23, 2015
Author(s)
Ndubuisi G. Orji, Hiroshi Itoh, Chumei Wang, Ronald G. Dixson, Sebastian Schmidt, Bernd Irmer, Peter S. Walecki
In atomic force microscopy (AFM) metrology, the tip is a key source of uncertainty. Images taken with an AFM show a change in feature width and shape that depends on tip geometry. This geometric distortion is more pronounced when measuring features with

Deep-subwavelength Nanometric Image Reconstruction using Fourier Domain Optical Normalization

November 5, 2015
Author(s)
Jing Qin, Richard M. Silver, Bryan M. Barnes, Hui Zhou, Ronald G. Dixson, Mark Alexander Henn
Quantitative optical measurements of deep sub-wavelength, three-dimensional, nanometric structures with sensitivity to sub-nanometer details address an ubiquitous measurement challenge. A Fourier domain normalization approach is used in the Fourier optical

Photomask Linewidth Comparison by PTB and NIST

November 2, 2015
Author(s)
Detleff Bergmann, Bernd Bodermann, Harald Bosse, Egbert Buhr, Gaoliang Dai, Ronald G. Dixson, W H?er-Grohne
We report the initial results of a recent bilateral comparison of linewidth or critical dimension (CD) calibrations on photo-mask line features between two national metrology institutes (NMIs): the National Institute of Standards and Technology (NIST) in

Lateral Tip Control Effects in CD-AFM Metrology: The Large Tip Limit

October 21, 2015
Author(s)
Ronald G. Dixson, Ryan Goldband, Ndubuisi G. Orji
Critical dimension atomic force microscopes (CD-AFMs) use flared tips and two-dimensional sensing and control of the tip-sample interaction to enable scanning of features with near-vertical or even reentrant sidewalls. Features of this sort are commonly

Interactions of Higher Order Tip Effects in CD-AFM Linewidth Metrology

April 30, 2015
Author(s)
Ronald G. Dixson, Boon Ping Ng, Xavier Bonnaud, Ndubuisi G. Orji
A major challenge in critical dimension atomic force microscope (CD-AFM) width metrology is accounting for the effects of the tip on the apparent features in an image. The overall effect of the tip is to broaden the apparent width of lines and narrow the

Technique for AFM Tip Characterization

September 15, 2014
Author(s)
Ndubuisi G. Orji, Ronald G. Dixson, Hiroshi Itoh, Chumei Wang
In atomic force microscopy (AFM) metrology, the scanning tip is a major source of uncertainty. Images taken with an AFM show an apparent broadening of feature dimensions due to the finite size of the tip. An AFM image is a combination of the feature shape

Effects of Lateral Tip Control in CD-AFM Width Metrology

August 12, 2014
Author(s)
Ronald G. Dixson, Boon Ping Ng, Ndubuisi G. Orji
Critical dimension atomic force microscopes (CD-AFMs) use flared tips and two-dimensional sensing and position control of the tip-sample interaction to enable scanning of features with near-vertical or reentrant sidewalls. Sidewall sensing usually involves

Distributed Force Probe Bending Model of CD-AFM Bias

April 1, 2013
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 technique. To characterize modern semiconductor devices, small and flexible probes, often 15 nm to 20 nm in diameter, are used. Recent studies have reported uncontrolled and significant