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Search Publications by: Richard A. Allen (Fed)

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Displaying 1 - 25 of 269

Optical Characterization of Parasitic Motion in a Long-Stroke Shaker

December 2, 2024
Author(s)
Jared Strait, Richard A. Allen
We present an optical scheme to simultaneously characterize the cross-axis and rotational parasitic motions of a long-stroke shaker. By leveraging the geometric properties of a corner cube retroreflector mounted on the shaker load table, we independently

Primary Sound Standard Based On Dynamic Fabry Perot Interferometry

September 21, 2023
Author(s)
Akobuije Chijioke, Richard A. Allen, Steven E. Fick, Benjamin Reschovsky, Jared Strait, Randall P. Wagner
We describe an optical sound standard in which the sound pressure is measured by using a high-finesse optical cavity to observe the induced change in the refractive index of the medium (acousto-optic effect). The optical refractive index of a substance

Optical-cavity-based primary sound standard

February 1, 2023
Author(s)
Akobuije Chijioke, Richard A. Allen, Steven E. Fick, David Long, Benjamin Reschovsky, Jared Strait, Randall P. Wagner
We propose an optical sound standard in which the sound pressure is directly measured by using an optical cavity to observe the induced change in the refractive index of air. In this method, an optical cavity is coupled with an acoustic cavity, with the

Intrinsically accurate sensing with an optomechanical accelerometer

May 18, 2022
Author(s)
Benjamin Reschovsky, David Long, Feng Zhou, Yiliang Bao, Richard A. Allen, Jason J. Gorman, Thomas W. LeBrun
We demonstrate a microfabricated optomechanical accelerometer that is capable of percent-level accuracy without external calibration. To achieve this capability, we use a mechanical model of the device behavior that can be characterized by the thermal

A Dynamic Uncertainty Protocol for Digital Sensor Networks

November 1, 2021
Author(s)
Michael Gaitan, Richard A. Allen, Jon Geist, Akobuije Chijioke
We propose a concept of the use of dynamic uncertainty to improve the accuracy and robustness of digital sensor networks. The digital smart transducer is integrated with a microcontroller that reads the binary data from the calibrated sensor, performs an

Laser-based comparison calibration of laboratory standard microphones

August 30, 2021
Author(s)
Randall P. Wagner, Richard A. Allen, Qian Dong
A precision laser-based comparison calibration method for laboratory standard microphones is described that uses reference microphones calibrated by the pressure reciprocity method. Electrical drive current and diaphragm velocity are measured while the

Nondestructive shape process monitoring of three-dimensional high aspect ratio targets using through-focus scanning optical microscopy Optical Microscopy

September 27, 2018
Author(s)
Ravikiran Attota, Hyeonggon Kang, Keana C. Scott, Richard A. Allen, Andras Vladar, Bunday Benjamin
Low-cost, high-throughput and nondestructive metrology of truly three-dimensional (3-D) targets for process control/monitoring is a critically needed enabling technology for high-volume manufacturing (HVM) of nano/micro technologies in multi-disciplinary

Improvements in Accelerometer Calibration at NIST Using Digital Vibrometry

April 29, 2017
Author(s)
Beverly F. Payne, Richard A. Allen, Colleen E. Hood
Improvements in shaker design and laser vibrometer development has provided more precise calibration of accelerometers. Calibrations are performed at frequencies from 1Hz to 20 kHz with improved uncertainty and improved efficiency. The vibrometer mounting

Bonded Wafers for Three-Dimensional Integration

March 2, 2017
Author(s)
Richard A. Allen
Three-dimensional (3D) integration is a key enabling technology for compact, high-performance, and/or low-power electronics. This technology enables the fabrication of circuits with functions that commonly cannot be fabricated on a single substrate in a

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

A ROUND ROBIN EXPERIMENT TO SUPPORT BOND VOID MEASUREMENT STANDARDS

May 1, 2016
Author(s)
Richard A. Allen, David T. Read, Victor H. Vartanian, Winthrop A. Baylies, William Kerr, Mark Plemmons, Kevin T. Turner
A round robin experiment to compare the sensitivities of various metrology tools to small voids between bonded wafers such as are used in three-dimensional stacked integrated circuits (3DS-ICs) and MEMS packaging. Participants received a set of four bonded

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

Metrology Needs for 2.5D/3D Interconnect

June 20, 2014
Author(s)
Victor H. Vartanian, Richard A. Allen, Klaus Humler, Steve Olsen, Brian Sapp, Larry Smith
This chapter will focus on the metrology steps to support 2.5D and 3D reference flows employing via-mid copper through-silicon via (TSV) processing, wafer thinning, and backside processing using a handle wafer and chip-to-chip bonding. Reference flows that

Metrology for 3D Integration

May 13, 2014
Author(s)
Richard A. Allen, Victor H. Vartanian, David T. Read, Winthrop A. Baylies
Three-dimensional stacked integrated circuit (3DS-IC) fabrication requires complex technologies such as high-aspect ratio through- silicon vias (TSVs), wafer thinning, thin wafer handling and processing, and bonding of thin wafers with complex patterned