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Search Publications by: Richard A. Allen (Fed)

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Displaying 1 - 25 of 134

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

Metrology Needs for TSV Fabrication

March 4, 2014
Author(s)
Victor H. Vartanian, Richard A. Allen, Larry Smith, Klaus Hummler, Steve Olson, Brian Sapp
This paper focuses on the metrology needs and challenges of through silicon via (TSV) fabrication, consisting of TSV etch, liner, barrier, and seed (L/B/S) depositions, copper plating, and copper CMP. These TSVs, with typical dimensions within a factor of

Detection of 3D Interconnect Bonding Voids by IR Microscopy

February 20, 2014
Author(s)
Jonny H?glund, Zoltan Kiss, Gyorgy Nadudvari , Zsolt Kovacs, Szabolcs Velkei, Moore Chris, Victor H. Vartanian, Richard A. Allen
There are a number of factors driving 3D integration including reduced power consumption, RC delay, and form factor as well as increased bandwidth. However, before these advantages can be realized, various technical and cost hurdles must be overcome. One

TSV Reveal height and bump dimension metrology by the TSOM method

April 30, 2013
Author(s)
Ravikiran Attota, Haesung Park, Victor H. Vartanian, Ndubuisi G. Orji, Richard A. Allen
Through-focus scanning optical microscopy (TSOM) transforms conventional optical microscopes into truly 3D metrology tools for nanoscale- to- microscale dimensional analysis with nanometer-scale sensitivity. Although not a resolution enhancement method

The MEMS 5-in-1 Test Chips (Reference Materials 8096 and 8097)

March 27, 2013
Author(s)
Janet M. Cassard, Jon C. Geist, Craig D. McGray, Richard A. Allen, Muhammad Y. Afridi, Brian J. Nablo, Michael Gaitan, David G. Seiler
This paper presents an overview of the Microelectromechanical Systems (MEMS) 5-in-1 Reference Material (RM), which is a single test chip with test structures from which material and dimensional properties are obtained using five documentary standard test

EVALUATING METHODS OF SHIPPING THIN SILICON WAFERS FOR 3D STACKED APPLICATIONS

November 7, 2012
Author(s)
Richard A. Allen, Urmi Ray, Vidhya Ramachandran, Iqbal Ali, David T. Read, Andreas Fehk?hrer, J?rgen Burggraf
An experiment was performed to develop a method for choosing appropriate packaging for shipping 300 mm silicon wafers thinned to 100 µm or less for three-dimensional stacked integrated circuits (3DS-ICs). 3DS-ICs hold the promise of improved performance

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

Rectangular Scale-Similar Etch Pits in Monocrystalline Diamond

September 15, 2011
Author(s)
Craig D. McGray, Richard A. Allen, Marc J. Cangemi, Jon C. Geist
Etching of monocrystalline diamond in oxygen and water vapor at 1100° C through small pores in a silicon nitride film produced smooth-walled rectangular cavities. The cavities were imaged by electron microscope and measured by interferometric microscopy

Test Structure Fundamentals

April 4, 2011
Author(s)
Richard A. Allen
Test structures are critical tools for semiconductor manufacturers, allowing for understanding of the process and individual circuit elements that cannot be acquired from measurements of the circuits, which can have billions of transistors and other

Intercomparison of Methods for Detecting and Characterizing Voids in Bonded Wafer Pairs

October 1, 2010
Author(s)
Richard A. Allen, Andrew C. Rudack, David T. Read, Winthrop A. Baylies
The Wafer Bond Task Force of the SEMI MEMS Standards Committee has begun a round robin experiment to evaluate methods for identifying and characterizing voids in bonded wafer pairs for three-dimensional integrated circuit (3D IC) applications. Due to 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

MEMS Young's Modulus and Step Height Measurements with Round Robin Results

September 30, 2010
Author(s)
Janet M. Cassard, Richard A. Allen, Craig D. McGray, Jon C. Geist
This paper presents the results of a microelectromechanical systems (MEMS) Young s modulus and step height round robin experiment, completed in April 2009, which compares Young s modulus and step height measurement results at a number of laboratories. The