Pollution prevention innovative technology.

DESIGNING FOR THE ENVIRONMENT - MOTOROLA TESTS LASER CLEANING RADIANCE PROCESS[SM] ON SEMICONDUCTOR WAFERS FAB

Radiance Services Company, Bethesda, MD, announced that a Radiance laser cleaning system, designed for applications in semiconductor manufacturing, is operating at Motorola's Phoenix Corporate Research Laboratory. The Microelectronics Research Laboratory (MRL) of the Department of Defense purchased the tool, built by Neuman Micro Technologies, Inc., of Concord, New Hampshire.

The MRL is working with Motorola to carry out a joint demonstration of the system's capabilities in cleaning silicon wafers, photomasks, and flat panel display substrates. The tool was funded under an Environmental Technology Initiative grant from the U.S. Environmental Protection Agency, which is co-managing the project with the MRL through its National Risk Management Research Laboratory. Dr. William Bandy, director of the MRL, said, "This is an unusual cooperative project to demonstrate the benefits of a new technology. All of the parties are seeking an improved, environmentally benign, economical means of cleaning semiconductor wafers and other electronics products."

Radiance system cleans surfaces with the patented Radiance [Process.sub.SM], which uses only laser light and a flowing inert gas, such as nitrogen, to lift unwanted material from the surface and sweep it away. The MRL holds a license for use of the Process and Motorola signed a research license in January, 1997. Neuman Micro Technologies has a license to build equipment applying the Process.

The Process has many potential cleaning applications in semiconductor and electronics manufacturing. These industries require extremely clean surfaces and currently use large amounts of ultrapure water and chemicals to remove particles and other contaminants, producing large amounts of waste water and accounting for approximately one quarter of the cost of making a computer chip. The Process can reduce water and chemical consumption and waste disposal costs, because it uses only laser light and non-toxic gases, such as nitrogen or argon. Donna F. Bethell, president of Radiance, said, "We expect that the Radiance [Process.sub.SM] can greatly reduce both capital and operating costs for semiconductor fabs. But its greatest benefit may well be in yield improvements, because wet chemical cleaning is reaching its limits at 0.2 micron but laser cleaning removes particles below 0.1 micron, down even to parts of molecules."

The project's first phase will last six months and will focus on a comparison of the cost and efficiency of the Radiance [Process.sub.SM] to water and chemical cleaning for silicon wafers; the tests will include removal of particles. The MRL will publish the results under the terms of the EPA grant. Paul Randall of the EPA's National Risk Management Research Laboratory said, "This technology shows potential for removing particles from semiconductor wafers without large amounts of water and chemicals. We are proud to support the Department of Defense and thank Motorola for generously hosting the project."

The MRL and Motorola also plan to test the Process on wafers with chemical-mechanical polishing slurry, chrome-on-quartz photomasks, which are used to make chips, and flat panel display substrates, which are used for computer screens. Better cleaning methods for all of these products can reduce costs and improve production yields, because a single contamination defect from a particle can ruin an entire chip and a few tiny defects can make a flat panel display unusable. Dr. Ronald Legge, project manager for Motorola, said, "Motorola is very pleased to help evaluate this exciting cleaning process. Economical contamination control and defect reduction are key ingredients for successful, competitive manufacturing and we want to stay in the forefront of developments."

The Radiance system was designed and built by Neuman MicroTechnologies, Inc. Newman president Orest Ohar said, "This system was designed as a prototype and versatile testbed for the Radiance [Process.sub.SM] and to demonstrate its ability to operate in a semiconductor manufacturing environment. Neuman will continue to support the tool and work with radiance and Motorola on future design variation for specific applications."

Radiance Services Company develops and markets applications for the Radiance [Process.sub.SM]. Other projects being carried out with U.S. companies include cleaning back-end-of-the-line wafers, tire molds, television glass, fuel injectors, brass door knobs, and jet turbine blades. The Process is patented in the United States, Europe, Canada, Russia, Australia, Taiwan, Hong Kong, and Singapore; there are patents pending in Japan, Korea, China, and 18 other jurisdictions.