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Benefits of NIST Data Are Worth 10 Times the Costs
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Ceramics
Benefits of NIST Data Are Worth 10 Times the Costs
The U.S. ceramics industry derives substantial economic benefits from NIST data evaluation services, according to an independent study by TASC Inc. The benefit-to-cost ratio of the Ceramic Phase Equilibria Program is estimated at 10 to 1, and the internal rate of return (commonly called the social rate of return when calculated for public-sector research) is estimated to be at least 33.5 percent. Both estimates are conservative. The results imply that the NIST program "is pursuing a socially valuable activity," the study concludes.
Phase equilibria diagrams help ceramic component manufacturers understand the effects of temperature, pressure and material concentrations on the processing and properties of ceramic products. In the CPEP, various data are evaluated to ensure accurate diagrams and that the overall data meet all industry R&D needs. The evaluated databases help manufacturers avoid duplicative research costs and efficiently overcome production difficulties.
For example, the study notes that accurate phase diagrams were essential in developing the most durable material composition for a component of the catalytic converters that now control emissions in 500 million cars and trucks worldwide. The TASC study focused on phase diagrams for advanced ceramics used in structural applications, such as cutting tools and heat engines. The benefit data were collected in telephone interviews with representatives of 28 companies ranging from large corporations to smaller speciality ceramic firms.
To request a single copy of Economic Assessment of the NIST Ceramic Phase Diagram Program, contact Denise Herbert, A1005 Administration Bldg., NIST, Gaithersburg, Md. 20899-0001. The study also is available on the World Wide Web (as an Adobe Acrobat file) at http://www.nist.gov/director/prog-ofc/report98-3.pdf.
Media Contact:
Michael Newman (301) 975-3025
Semiconductors
Partners Fill Big Need With Better SRMs for Shrinking Chips
In an effort to keep up with the galloping pace of technological change in the semiconductor industry, NIST has teamed with VLSI Standards Inc. of San Jose, Calif., to improve the availability of thin-film reference materials tailored for industry. Through a cooperative research and development agreement, NIST worked with VLSI Standards to establish a traceability pathway to NIST standards for the company's new 4.5 nanometer (billionth of a meter) and 7.5 nanometer thin-film reference materials.
Made of silicon dioxide, these thin films are needed by the semiconductor industry to calibrate ellipsometers used for process development and process quality control when making very large-scale integrated circuits. NIST enabled the company to establish its measurement "traceability" by carefully characterizing the company's current thinnest reference materials with NIST's primary, high-accuracy ellipsometer. Currently, the thinnest silicon dioxide Standard Reference Materials available from NIST are 10 nanometers thick, provided on wafers with 76 millimeter (approximately 3 inch) diameters.
VLSI's new reference materials will be provided in 150 millimeter (6 inch) and 200 millimeter (8 inch) diameter wafers currently more common in industry.
For more information, contact Barbara Belzer, NIST, (301) 975-2248, or Prabha Durgapal, VLSI Standards Inc., (408) 428-1800.
Media Contact:
Michael Newman (301) 975-3025
Time
Seven Trapped Ions Make a Better Clock
The key to improving atomic timekeeping is the ability to better determine the frequency of the atoms involved. The more atoms that you have and the longer you can observe them, the better that ability grows. Currently, the best cesium-beam clocks are limited by the fact that atoms speed through the apparatus at bullet-like velocities, giving the scientist only a fleeting glance at each one. A new technique called the atomic fountain gently tosses the atoms straight up and lets them fall back through the measuring apparatus. This extends the observation time and greatly improves the clock's performance.
NIST's Time and Frequency Division in Boulder, Colo., is studying a promising alternative: trapping the atoms in a net of electromagnetic waves and then laser cooling them to near absolute zero. This would allow the atoms to be scrutinized for much longer periods than are currently achievable. In addition, trapping and cooling many atoms instead of just a few will greatly strengthen the signal.
NIST researchers have succeeded in trapping seven mercury atomic ions and examining them for up to 100 seconds at a time. This allows their characteristic frequency to be determined with an accuracy and precision that approaches the best results yet obtained from atomic fountains. Hopefully, the technique can be extended to collections of several dozen ions, so that the next generation mercury ion clock may surpass even the cesium fountain's performance.
A paper, no. 12-98, describing the work is available from Sarabeth Harris, MC 104, NIST, Boulder, Colo. 80303-3328, (303) 497-3237.
Media Contact:
Collier Smith (Boulder) (303) 497-3198
Standards
Comments on Softwood Lumber Standards Sought
Voluntary Product Standard PS 20-94, American Softwood Lumber Standard, is used by the softwood lumber industry to provide for uniform, industry-wide grade-marking and inspection requirements for softwood lumber here and abroad. In addition, it serves the procurement and regulatory needs of numerous federal, state and local government agencies. The implementation of the standard also allows for uniform labeling and inspection of treated wood products.
As part of the five-year review of the standard, NIST is seeking public comment on the standard during the next three months.
The American Lumber Standard Committee, the standing committee that is responsible for maintaining and interpreting PS 20-94, will assist NIST in determining the technical adequacy of the standard, the level of acceptability the standard has among the various segments of the softwood lumber industry, the standard's compatibility with existing law and established public policy, and the benefits that would be derived from PS 20-94 versus any alternatives. Upon completion of the review, the ALSC and NIST will reaffirm, revise or withdraw PS 20-94 as appropriate.
Comments on PS 20-94, supported by data, views or arguments, should be submitted to NIST no later than June 30, 1998.
Comments may be sent to Barbara M. Meigs, Rm. 164, Bldg. 820, NIST, Gaithersburg, Md. 20899-0001, fax: (301) 926-1559. The text of PS 20-94 may be found on the World Wide Web (as an Adobe Acrobat file) at http://ts.nist.gov/ts/htdocs/210/sccg/ps20-99.pdf. For those without access to the Web, a printed copy may be obtained from the address above.
Media Contact:
Michael Newman (301) 975-3025
Physics
NIST Lab Upgrades Scientific Data on Web
NIST World Wide Web pages offering free and easy access to scientific data are among the Institute's most popular, getting thousands of "hits" per month from computer users around the world. Now NIST has improved, expanded and integrated the data offered on some of these pages into a new easy-to-use site: http://physics.nist.gov/cuu. This public resource provides in-depth information on the fundamental physical constants, the International System of Units (the modern metric system known as SI) and the expression of uncertainty in measurement.
Any computer user with access to the Web can use this site to look up values of fundamental physical constants and conversion factors of physics and chemistry. These values are searchable in an easy-to-print form.
The metric information section contains a concise summary of the essential features of the SI, and the rules and style conventions for its use. In addition, the section details the seven SI base units and the 21 SI-derived units with special names and symbols. Electronic publications discussing use of the SI are also available.
The section concerning uncertainty covers evaluating and expressing the uncertainty associated with measurement results. A helpful publication from NIST and the citations of related publications of the International Organization for Standardization are posted in this section.
Media Contact:
Michael Newman (301) 975-3025
Optoelectronics
Partners Create New Detector for Fiber Power Measurements
Scientists at NIST, Motorola Inc. and Boulder Metric Inc. have designed and built an optical detector that can be used for the calibration of optical fiber power meters that incorporate various types of fibers and fiber connectors. The new device provides a convenient means for high-accuracy optical radiation measurements where a large numerical aperture is needed.
The detector was evaluated at NIST's calibration facility and then tested by Motorola in a production measurement environment. The three partners believe the detector could serve as a viable commercial product for many U.S. businesses that manufacture and measure fiber optic/optical communication test equipment.
Technical information is available from John H. Lehman, MC 815.01 NIST, Boulder, Colo. 80303-3328, (303) 497-3654. A paper, no. 11-98, explaining the detector is available from Sarabeth Harris, MC104, NIST, Boulder, Colo. 80303-3328, (303) 497-3237.
Media Contact:
Fred McGehan (Boulder) (303) 497-3246
Materials Reliability
Tensile Testing of Thin Films Showcased in Reference Set
S ince all microchips contain thin films, it is critical that manufacturers be able to assess their reliability. If the mechanical properties of the films themselves or their interfaces to other materials fail, then the electrical function of the devices they support will fail as well. Unfortunately, traditional mechanical test techniques are not suitable for these thin films.
NIST recently published a collection of five technical papers about the development of a set of techniques for measuring the tensile properties of thin films. In this reference, thin films mean metal layers produced by physical vapor deposition or electrodeposition, with thicknesses around one micrometer. The described apparatus tests specimens whose gauge section is typically 0.8 millimeters long and 50 to 200 micrometers wide. Specimens with thicknesses ranging from 0.3 to 15 micrometers have been tested.
Topics discussed in the papers include "A New Method for Measuring the Strength and Ductility of Thin Films," "Mechanical Behavior of Aluminum and Copper Thin Films," "Fatigue of Microlithographically Patterned Free-Standing Aluminum Thin Film Under Axial Stresses," "Tension-Tension Fatigue of Copper Thin Films" and Piezo-Actuated Microtensile Test Apparatus." Also included are detailed mechanical drawings of the piezo-actuated microtensile test fixture and the current versions of the software used to control the tensile tests and reduce the data.
For copies of Tensile Testing of Thin Films: Techniques and Results, contact David T. Read, MC 853.08, NIST, Boulder, Colo. 80303-3328, (303) 497-3853.
Media Contact:
Fred McGehan (Boulder) (303) 497-3246
U.S. Department of Commerce
Technology Administration
National Institute of Standards and Technology
Editor: Michael Newman
HTML conversion: Crissy Wines
Last updated: May 12, 1998
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