RESEARCH AND TECHNOLOGICAL DEVELOPMENT ON STANDARDS, MEASUREMENTS AND TESTING IN THE USA
Robert E. Hebner
National Institute of Standards and Technology, USA
It is with great pleasure and humility that I accepted the invitation to speak at the 25th anniversary conference of the BCR (Bureau Communautaire de Reference). The BCR, as part of the European Commission, and the National Institute of Standards and Technology (NIST), as part of the U.S. Department of Commerce, each recognize that measurement capability is an essential ingredient of trade and regulation. Consequently, both organizations are directing research toward assuring that an adequate measurement base will exist to support efficient trade and regulation as products and processes grow in technological sophistication and complexity. I am pleased to learn about what you are doing and to share with you this brief summary of our work.
We in the U.S. Department of Commerce are particularly comfortable with the theme of this conference, Measurements: a key to competitiveness. There has never been a time in which measuring accurately has been more important to a nation's economic health. This is an age in which semiconductor devices shrink to half their previous size every 18 months and measurement advances depend on microscopes that "see" individual atoms. The longevity and reliability of car engines depend upon manufacturing tolerances of micrometers - about the width of a single bacterium. Our global communication systems rely on accurate clocks synchronized to within a millionth of a second. Treatment of many diseases relies on carefully quantified doses of radioactive drugs. A nation's measurement infrastructure is growing in strategic importance. It's easy to understand why. Global market competition is becoming more technology intensive, and trade -- especially, exports of high-technology products -- is becoming a more significant determinant of economic health.
NIST performs cutting-edge scientific research to provide the measurements, standards, and metrology systems needed by industry to develop and trade in new products and by government to support intelligent regulation. Of NIST's appropriated annual budget of about $650 million, $275 million supports standards and measurement-related research and services. Outputs of these activities include: 2,000 technical publications, nearly 9,000 user-paid calibrations and tests, and sales of 38,000 Standard Reference Materials (SRMs) and 5,300 Standard Reference Data database units. These are needed to support one of the largest and most technically advanced economies in the world.
Further, NIST has two programs designed to accelerate technology development and improve business performance. The Advanced Technology Program (ATP) is a unique partnership between government and private industry. The ATP accelerates the development of high-risk enabling technologies that are essential to the development of new products, processes, and services that are still years away from the market or from industrial practice. Research priorities for the ATP are set by industry, but the program only selects projects that promise significant commercial payoffs and widespread benefits for the economy. Small and medium-sized manufacturers are given the help they need to succeed through the Manufacturing Extension Partnership (MEP). In the United States, the closest parallel to this outreach system of technical assistance is the model of U.S. agricultural extension centers that help farmers to learn about and adopt modern agricultural practices. MEP centers are located in all 50 states and Puerto Rico. They provide even the smallest firms with access to more than 2,000 knowledgeable manufacturing, business, and trade specialists. Each Center has the ability to provide technical and business solutions to help businesses improve performance and increase sales and exports.
In the late 1980's, NIST was given responsibility for establishing a national quality program, including the annual selection of companies that win the Malcolm Baldrige National Quality Award. The program's approach is nearer to measurement than to prescription. We worked with industry, in the U.S. and around the world, to understand ways to determine the degree to which an organization has achieved quality business processes. The results of this research have been translated into the Baldrige Award criteria, which are regularly reviewed and updated. About 40 companies have won the award, but more than a million copies of the criteria have been distributed worldwide. Many companies use the Baldrige criteria to improve their operations, and to evaluate their quality improvement efforts. NIST also uses the criteria in its own activities. As for the award process, up to two Malcolm Baldrige National quality Awards may be given each year in each of three categories: 1) manufacturing companies, 2) service companies, and 3) small businesses. As a result of recent legislation, the 1999 awards will be expanded to five categories, including education and healthcare organizations. Seventy-eight percent of CEOs recently surveyed found the program either "extremely valuable" or "very valuable" in stimulating improvements in quality in businesses. The most visible indicator that the criteria are measuring quality in a way that has a positive effect on the bottom line, however, is the fact that the winners' stock has outperformed the Standard and Poor's 500 by a factor of three.
NIST Measurement Support for Trade
Trade policies and agreements are vitally important to efforts to create a world market with a "level playing field." Increasingly however, sophisticated measurements, conformity tests, normative standards, and reference materials and data are required to trade successfully in the world market. To meet these needs, the U.S., with support from NIST, is working to enhance and strengthen its voluntary standards system so that it may provide input into international standards development and to streamline its development process to meet rapidly changing industrial needs.
On September 23, 1998, in conjunction with the U.S. celebration of World Standards Day, NIST and the American National Standards Institute (ANSI) co-hosted a summit to discuss issues in developing, supporting, and using national and international standards, especially those that significantly affect U.S. manufacturers and exporters. Representatives from standards-developing organizations, industry, government, consumer, and other stakeholder groups, participated in discussions to develop a more effective national standards strategy that will meet the needs of both the private sector and the government.
Standards development processes will benefit from a careful self-examination. Many of today's processes were developed during an earlier time when business practices were much different. Today, standards must not merely cope with, but actually enable change. Standards are vehicles for reducing cycle times; fostering new methods, such as rapid prototyping, virtual and distributed manufacturing, and enabling rapid, effective introduction of new technology into products and processes. Moreover, small companies develop much of the newer technology, and the system must assure that they have the same real opportunity to influence international standards as do multinational corporations.
While industry is examining its standards system, NIST is helping the existing system to be as effective as possible. For example, STEP, the international Standard for the Exchange of Product Model Data, provides the standardized representations of product information needed for electronic communication between engineering and manufacturing. To move STEP to an international standard in a timely manner, the ISO STEP Committee changed the normal ISO procedures and approved electronic distribution of the draft standards and electronic submission of comments. NIST has served as the secretariat of this subcommittee since its inception, and has experimented with methods to expedite STEP's development and adoption.
Another example of a new standards development process is the Versailles Project on Advanced Materials and Standards (VAMAS). Its purpose is to stimulate advanced materials trade through pre-standards research. This is a highly successful ongoing cooperative effort among the original G-7 countries and the European Community to draft guidelines, codes of practice, and specifications to harmonize materials test methods. The result of this pre-standards work has been to accelerate the adoption of harmonized international standards, eliminate technical trade barriers in new technologies incorporating these materials, and help to set research spending priorities in cooperating nations.
To continue global trade expansion, it is necessary to increase the involvement of regional metrology organizations to assure uniform and accurate measurements globally and in a cost-effective manner. Comparisons between individual nations for all quantities and ranges of interest would be prohibitively time consuming and expensive. Rather, traceability between individual laboratories can be assured through a system of regional organizations linked through key comparisons.
Laboratory accreditation, product certification, and management systems are too often used as non-tariff trade barriers. Where one or more of these processes is needed to improve confidence between buyers and sellers or by regulators, NIST is working to assure that the systems are open and add value, rather than cost. They must be a stimulus to get innovative products to market faster and cheaper than if these processes were not in place.
SIM - NET will be a step toward establishing mutual confidence in a less costly and faster manner. This network, which is currently under development in the Americas, will provide a method for remotely collaborating, in real-time, on the calibration of electrical standards using transportable digital multimeters. This system, if successful, will be expanded to accommodate more types of measurements and to include all nation's participating in the Inter-American Metrology System. It will allow metrologists from all over the Americas to work together efficiently to assure a common measurement base.
NIST Measurement Support for Society
Safer radiometry, more confidence in nutritional labeling, reduced fire damage, and speedier product development are some of the practical advantages to society of NIST research. Several hundred laboratory projects are under way at NIST during a single year. Some examples described below illustrate how measurement capability helps to ensure the health and safety of the public, protect the environment, and advance the work of the criminal justice community.
NIST provides standards to assure the safety of the patient and operator for all aspects of the mammography procedure. Optical-density, step-tablet standard reference materials (SRMs) measure film performance; a "kVp" standard ensures proper spectral distribution of x-rays, and a new national standard for mammography radiation dose can be used with all 17 different types of machines now in use.
Working with the U.S. Environmental Protection Agency (EPA), NIST established a system for accrediting companies and interested states to provide NIST-traceable proficiency testing for regulated chemical, microbial, radiological, and toxicological parameters in drinking water and wastewater. Since the 1970's, EPA has conducted semiannual proficiency testing of more than 4,000 public and private sector laboratories. Now, in addition to EPA, an expanded network of companies and states will be able to conduct proficiency testing, greatly increasing the number of laboratories that can be accredited.
Screening of new materials for longer-lasting orthopedic implants has been improved because NIST and four companies have teamed up under cooperative research and development agreements to construct an apparatus to study how potential, alternative implant materials hold up under the effects of motion, environment, and a variety of stress-loading cycles. The old testing process, which hampered the search for better materials, took about six months, as compared to one week with the new apparatus.
The Nutrition Labeling and Education Act (U.S. Public Law 96-359) requires that nutritional information be provided for all packaged foods sold in the U.S. In addition, the Infant Formula Act (U.S. Public Law 101-535) requires that specific nutrients contained in infant formula fall within a specified range or above a specified range or above a specified minimum. NIST is in the process of certifying a number of natural matrix SRMs for selected vitamins, cholesterol, fatty acids, and minerals as well as for toxic trace elements to improve business and consumer confidence in the measurement process.
America's nuclear power reactors were in danger of being shut down prematurely because of inaccurate estimates of radiation embrittlement of the reactor vessel. NIST researchers found that reactor vessel embrittlement can be characterized by nondestructive nonlinear ultrasonic and micromagnetic measurements made directly on the vessel. With these methods, NIST determined that copper-containing welds have little effect on the lifetime and performance of the steel. The result is an improved assessment of radiation embrittlement and better predictions of crack-arrest toughness, thus providing critical information on reactor safety and preventing premature closure of eleven nuclear facilities at a cost of more than $3 billion.
The cost of full-scale fire tests on industrial facilities can run to millions of dollars. NIST has developed methods to measure the performance of fire-control technologies. It has coupled these with a new computational method to assess the performance of fire-protection systems in industrial facilities and to improve the accuracy of fire simulations. As a result, the performance of sprinklers, draft curtains, and vents can now be simulated as accurately as conducting a full scale test costing upwards of $50,000.
In conjunction with the EPA, NIST has initiated a new quality assurance activity to assist the Aluminum Manufacturers' Association in the monitoring of gases that may contribute to global warming. These gases are emitted from aluminum processing plants when the extraction process has become inefficient.
NIST, through the National Voluntary Laboratory Accreditation Program, accredits laboratories for asbestos analysis in public buildings. This 10-year-old program has set up a suite of reference materials and reference methods for characterizing materials, and it has specified quality and technical requirements for the laboratories. Two programs have been instituted, one for analyzing asbestos in building materials, (e.g., wallboard, floor tile, etc.) and the second for analyzing asbestos in air.
Monitoring networks have been established by a number of government agencies to measure the solar ultraviolet radiation that may be associated with changes in atmospheric ozone, the incidence of skin cancer, changes in the growth patterns of crops and forests, and other effects. Significant variations, as large as 10 percent, have been observed between the spectral irradiance scales used by the networks and the scale maintained by NIST. A recent comparison, sponsored by NIST and the National Oceanic and Atmospheric Administration (NOAA), was held to characterize parameters that affect the accuracy of instruments deployed in solar UV monitoring networks. The collaborative effort also made synchronized solar scans to compare the performance of different instruments.
The NIST Office of Law Enforcement Standards applies science and technology to the needs of the criminal justice community, including law enforcement, corrections, forensic science, and the fire service. While the primary focus is on the development of minimum performance standards, which are promulgated by the sponsoring agency as voluntary national standards, the office also undertakes studies leading to technical reports and user guidelines. A small sample of the over 50 projects currently under way is described below.
During the past several years, the office has funded fundamental research and development on DNA forensic testing, with the goal of providing NIST traceability to all U.S. crime laboratory measurements of DNA for human identification. This work has culminated in two SRMs for nuclear DNA testing and a soon-to-be-released SRM for mitochondrial DNA testing. These NIST reference materials are now included as part of the FBI's Quality Assurance Standards for Forensic DNA Testing Laboratories.
Studies have shown that crime laboratories are using a variety of approaches for extracting drugs-of-abuse from hair. Although the laboratories can successfully detect and quantify drugs that are present with good accuracy, there is a significant level of false positives. Current research is exploring new, potentially more reliable, techniques, such as the use of saliva as a diagnostic sample medium, correlating drug concentration in saliva with that in blood, and using electrophoresis for the rapid separation and determination of drug concentration. In addition, a program of continued quality assurance is under deployment to forensic laboratories.
As part of an update of the existing National Institute of Justice standard for body armor, NIST is determining methods and protocols for testing contemporary protective materials used for armor protection. This includes determining an analytical technique for evaluating and ranking the threat ammunition poses to individuals, and developing new measurement techniques to estimate the protection provided by armor with respect to blunt trauma.
NIST Measurement Support for Industry
NIST was established to assist industry in the development of technology needed to improve product quality, to modernize manufacturing processes, to ensure product reliability, and to facilitate rapid commercialization of products based on new scientific discoveries. It does this by providing technical leadership for the vital base measurement units that support the nation's technology infrastructure as well as derived units that are more directly applied to industry measurement problems. Examples of some of these applied measurements are described below.
National Semiconductor Metrology Program
Fast-paced development in the semiconductor industry requires dramatically improved measurement tools to keep advanced microelectronic manufacturing competitive. The National Semiconductor Metrology Program (NSMP) conducts, often with industrial collaborators, projects associated with chip lithography, interconnectivity, materials and bulk processes, and packaging. NSMP draws on a full range of NIST expertise in semiconductor metrology to meet the metrology needs of materials, equipment, instrument, and device manufacturers. Projects focus on mainstream silicon CMOS (complementary metal-oxide semiconductor) technology addressed by the National Technology Roadmap for Semiconductors. Some example projects are described below.
The scanning electron microscope (SEM) has become the instrument of choice for in-line process inspection and metrology. Scanning probe instruments, such as the atomic force and scanning tunneling microscopes, have recently emerged to both complement and extend the capabilities of SEMs. NIST is exploring potential by means of a tool that is unique. The tool is the marriage of a compact scanning probe instrument with a high-resolution field emission SEM. The combination of these two techniques is expected to yield an instrument with superior qualitative and quantitative capabilities, which will be a great aid in the development of standards for semiconductor manufacturing.
Improvements in our understanding of the mechanisms responsible for the formation, transport, and growth of particles are necessary to minimize microcontaminants in semiconductor processing. NIST is using both measurement and modeling techniques in order to gain an understanding of these physical and chemical particle growth mechanisms in the gas phase in order to develop microcontamination standards for the industry.
As semiconductor gate dielectrics reach atomic dimensions, their electrical performance will become more difficult to predict and control with traditional optical tools used during fabrication. There is a critical need for reference materials and an accurate knowledge of layer structure so that optical measurements will be better predictors of the electrical properties of the films. NIST is developing more effective traceability mechanisms for reference materials, developing accurate optical function data at processing temperatures for crystal silicon and critical dielectric films, and improving the understanding of structural properties of gate films.
Thin-film conductors are an essential component of all advanced electronic devices. NIST is developing the metrology for evaluating the reliability of electrical interconnects, for measuring pertinent mechanical properties of thin metal films, and for understanding the microstructural processes that affect reliability. Two reliability test patterns have been designed to evaluate the major failure mechanisms of thin-film conductors. A third is under way.
Polymers are widely used in electronic packaging in many applications. Often, the polymer is in the form of a thin film on another material with significantly different physical properties. Knowing and predicting the dimensional changes of these films with temperature and humidity are important for modeling the performance and reliability of complex assemblies. This work is providing industry with robust measurement tools and data for characterizing the dimensional stability of thin-film polymers.
NIST has developed a testbed for validating the performance of models for widely used power transistors (insulated-gate bipolar transistors, IGBT). This testbed has been used to evaluate the component libraries in commercial circuit simulators. As a result, a major circuit simulator software vendor has made changes that substantially improve the accuracy of its IGBT component library.
Applied Measurements to Support Industry
The semiconductor industry is not the only high technology industry. In fact, technology is improving nearly all industrial activities. For example, NIST is developing measures and models that increase the accuracy and productivity of high-speed machining processes for a wide range of tools, workpiece materials, and configurations. Sample cost savings that can be achieved by industry are $65,000 for an aircraft brake using a single aluminum part to replace the expensive composite part. Ultimately, entire aircraft wings could be machined in only two parts using these techniques.
Through a NIST-led national and international effort, the quality and consistency of hardness testing for advanced ceramic materials has been improved by a factor of four. Hardness testing procedures can now be reliably used for specifications for critical applications, such as surgical implants, heat exchangers, and engine components.
NIST is quantifying the error in dimensional measurements made with laser tracker systems to decrease tolerances in large-part manufacturing. Many large-scale parts lack interchangeability due to dimensional variation. Large commercial aircraft may require more than one ton of shims, which results in additional operational costs of nearly $1 million per year per plane and requires custom-made replacement parts. NIST is participating in national and international standard bodies to ensure that domestic manufacturing needs are met.
The computer magnetic hard disk drive industry is increasing drive size by 60 percent per year and will need recording heads with nanosecond switching times within the next decade. However, using optical sampling and inductive techniques with unprecedented temporal, spatial, and dynamic resolution, NIST is now able to measure subnanosecond-switching times in magnetic recording head material, five times faster than any previously measured switching time. NIST also has measured critical processing parameters for creating giant magnetoresistance, a technology that will be the basis for the next generation of disk drive read heads.
Software quality is an increasingly visible problem. NIST is actively working to develop tests and standards to measure software performance. At the request of the Institute for Interconnecting and Packaging Electronics (IPC), NIST has developed a software program to test whether software complies with an IPC standard designed to improve the transfer of information from computer-aided-design (CAD) tools, to computer-aided-manufacturing (CAM) tools. IPC views this software test program as a key element needed to decrease the critical time-to-market for electronics manufacturers.
Rapid changes in technology and the globalization of commerce have put traditional measurement systems under pressure to change. No longer can we afford to select which comparisons to conduct between national laboratories based on ad-hoc experiential data. We need to use the latest information technology tools to acquire reliable comparison data. The data must be accessible to all in a usable fashion. We must use reliable, rigorous methods to determine whether we are, or how we can, meet international traceability requirements to ensure free-flowing global trade in all goods and services, but especially high-technology products. Finally, we must do all of this at a cost commensurate with the benefit and at a speed that accelerates, not impedes, time to market.