NIST Industrial Impact Company: Honeywell, Inc., Minneapolis, Minn. Company: Advanced Micro Devices, Austin, Texas When a new factory costs more than $1 billion, it might be expected to function perfectly. But money does not buy perfection in the semiconductor industry, where, despite sky-high manufacturing costs, declines in equipment performance and process faults not only occur but also go undetected for too long. “Sometimes you don’t know about faults until you have processed significant numbers of lots of materials,” says Steve Nettles of Advanced Micro Devices (AMD), a major semiconductor manufacturer. “We needed a way to find out about them more quickly.” So they found a way. With co-funding from NIST’s Advanced Technology Program (ATP), AMD teamed with Honeywell, Inc., which makes control systems for the oil and gas refining and pharmaceutical industries, and SEMATECH, an industry consortium that coordinates research and technology transfer, to design and demonstrate the software architecture, integrated components, and specifications needed for supervisory-level control of semiconductor manufacturing. In software lingo, the new technology is called an advanced process control (APC) framework, a high-level form of what is known more generally as a manufacturing execution system (MES). Although the technology is just now being commercialized, the ATP project already has produced measurable benefits for the semiconductor industry, a major driver of the U.S. economy:
“It was supposed to be an R&D project, and just through the success it took off faster than we expected.... This has probably had the biggest direct impact on manufacturing of any application that we have deployed,” says Nettles, a software specialist. “It is now cited as a very positive example of what MES can do to affect manufacturing performance.” More importantly from a national perspective, U.S. firms now have a head start of up to two years on foreign competitors in implementing APC as well as ownership of a valuable new technology—major benefits in a highly competitive international market, according to Tom Hill, the ATP project manager for Honeywell, the official team leader. The software fills an important need identified in the National Technology Roadmap for Semiconductors, which says APC is among the technologies that will enable the industry to maintain its historical 25 percent to 30 percent annual growth in productivity. In the past, the major barrier to the adoption of APC was the high cost and risk associated with time-consuming custom integration of individual controllers into existing manufacturing systems. Furthermore, process control systems were inflexible, and methods for collecting and analyzing process data were inadequate. The 27-month ATP project, which ended in mid-1998, overcame these barriers by bringing together partners with complementary expertise, hastening the development of a flexible, universal toolset that can be deployed rapidly across process areas and factories with minimal, one-time custom integration. Starting with SEMATECH’s framework for computer-integrated manufacturing, Honeywell and AMD worked together to gather and analyze requirements, design and develop software components and interfaces for various tasks, validate them in an iterative process, and add them to the framework. They also developed specifications that are in the process of becoming industry standards. The APC framework coordinates various types of MES, process control tools, and wafer fabrication equipment. Process data are collected by either the manufacturing equipment or sensors and fed forward or back to the controller. The software not only detects and classifies faults immediately but also adapts processing as needed from one run (e.g., wafer or batch) to the next, by tweaking the “recipes.” The APC system determines the appropriate parameters and manipulates the values based on process or material conditions. Specific advances achieved in the project include a 27 percent reduction in the standard deviation in oxide-removal rate during wafer polishing, a step that prepares the wafers for photolithography. The result is flatter, defect-free surfaces that improve the performance of semiconductor devices and reduce scrap. The project also reduced variability in critical dimensions, such as line width, which affect microprocessor speed. Variability in speed was reduced by 48 percent, and mean speed was increased by 15 megahertz without losses in yield. This advance enabled AMD to bring microprocessors with higher clock speeds to market faster than otherwise would have been possible, substantially increasing revenues. In addition, photolithography rework was reduced by 83 percent, saving time and money and increasing product yield. Finally, run-to-run controls can now be implemented up to four times faster, and with less staffing, than was previously possible, and controllers can be enhanced in hours or days instead of weeks or months. The APC system continues to provide a strategic advantage by enabling AMD to control what were once inherent variabilities and consistently achieve process targets. The APC technology has been licensed to ObjectSpace Fab Solutions of Austin, Texas, a project subcontractor, which will commercialize it in early 1999. Semiconductor firms and suppliers in the United States and Asia are expressing “significant interest” in the technology, according to Alan Weber of ObjectSpace. Pilot systems already have been developed for Motorola, Inc., and IBM Microelectronics. The ObjectSpace product is the only one of its type on the market that offers third-party integration, can be scaled to a whole factory, and covers all process areas, Weber says. “There is clear demand for APC in wafer fabrication as feature sizes shrink and manufacturers move to larger wafers, and the open architecture approach to APC deployment is showing real technical and commercial viability,” he adds. As a result of the success of the ATP project, AMD has created a corporate-level APC Department with a staff of more than 20, the new framework is in the process of becoming a Semiconductor Equipment Manufacturers International standard, and suppliers for the semiconductor industry are beginning to make APC-compliant system components. In addition, Honeywell is looking for ways to adapt the framework for use in its core business areas, Hill says. March 1999 |