Canon's New IDEAL Exposure Method Pushes Optics Into the Realm of NGL.

SANTA CLARA, Calif.--(BUSINESS WIRE)--Feb. 12, 1999--The recent flurry of activity relating to next generation lithography (NGL) may be a bit premature, considering a new Canon optical lithography extension technique called IDEAL.

"What we are seeing," says Dr. Nobuyoshi Tanaka, director and chief executive of Canon Optical Products Operations, "is that IDEAL technology, used with ordinary optical steppers or scanners, can extend the resolution to one-half the wavelength of the illumination light--for various types of patterns, and with excellent CD control and DOF."

IDEAL (Innovative Double Exposure by Advanced Lithography) is a patented multilevel imaging system that effectively reduces the photo process k1 factor to 0.3. This allows, for example, a 0.6 NA KrF exposure tool to resolve 120nm device features, or a 0.7 NA 193nm tool to print features in the 80nm region.

"The IDEAL method represents a significant breakthrough in optical lithography that has yet to be factored into the SIA Roadmap," says Dr. Tanaka. "If it is used with 157nm tools, IDEAL could potentially shift the NGL insertion node down to the 50nm region." Canon is now evaluating 157nm optical lithography designs that, when used with IDEAL technology, would enable resolution down to 60nm--well below the current SIA roadmap 90nm insertion node for NGL.

Canon will describe its IDEAL technology in detail on March 18 at the SPIE Microlithography '99 conference in San Jose.

Canon is already optimizing its steppers and scanners for IDEAL technology. The process began in 1997 when it launched an across-the-board reengineering program in its Utsunomiya factory. One aspect of this extensive program is its new lens tuning method based on Zernike coefficient analysis, which has reduced residual wavefront aberration by a factor of 4 or 5 from what it was achieving at the start of the program.

"Having an error free wave front will be a vital issue for all lens manufacturers," says Dr. Tanaka, "because, with the potential for enhanced resolution, lens aberrations will become a much more serious consideration from now on. The improvement achieved by these new tuning methods is not limited to current stepper and scanner lenses. It also allows future lenses to be designed for dramatically lower aberration in the first place."

As for eventually providing post-optical NGL options for its customers, Dr. Tanaka says Canon is well poised for the developing technologies because it has explored most of them before. "Canon has traditionally been way ahead of the curve in advanced lithography research, having pioneered the development of x-ray and extreme ultraviolet (EUV) lithography as well as e-beam direct write way back in 1982," Dr. Tanaka says. As a result, Canon has accumulated a large portfolio of intellectual property which covers most of the fundamental aspects of EUV lithography. And, later this year, we will ship the industry's only production lithography tool which can resolve 70nm, our new proximity x-ray stepper.

"All of the NGL approaches pose serious technology hurdles, but we have the resources to pursue those that look promising, including high-speed direct-write e-beam," Dr. Tanaka says. "But, while Canon continues to maintain aggressive development programs for post optical lithography, we believe that the introduction of any of the NGL methods into mainstream production is far into the future."

Dr. Tanaka stressed Canon's belief that optical lithography using the IDEAL method holds the most promise, and provides the most flexible options, for practical everyday manufacturing for many years to come.

The Semiconductor Equipment Division of Canon U.S.A., Inc., based in Santa Clara, Calif., supplies step-and-repeat and step-and-scan photolithography tools for manufacturing integrated circuits and large active matrix liquid crystal flat panel displays.

Canon U.S.A., Inc., headquartered in Lake Success, N.Y., is an industry leader in professional and consumer imaging equipment and information systems. It employs 10,000 people at more than 30 facilities throughout North, Central and South America and the Caribbean.

Canon, Inc., comprising all Canon Group operations, has over 78,000 employees.. Its headquarters are in Tokyo, Japan, with approximately 80 sales companies, manufacturing companies and R&D centers, worldwide.