San Jose, Calif. - During a presentation at the recent SPIE Advanced Microlithography conference here, Bryan Rice, director of lithography at chip making consortium Sematech, literally passed a hat along the front row of the audience. "We need money to solve the problem," he said.
It got laughs. But the laughter quieted when the Sematech researcher confessed that the industry still does not have the necessary inspection tools for extreme ultraviolet lithography, despite an R&D effort that has stretched over decades.
And if chip makers can't inspect EUV-enabled masks-which must be defect-free-EUV will not succeed.
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The EUV camp dropped the ball, believes Brian Grenon, an expert in the photomask field and president of Grenon Consulting Inc. "They should have invested in mask [and related inspection] technology in the first place," he said. "All of the sudden we found out about the mask issues. To me, that's insanity."
Sematech recently launched a consortium to develop the needed metrology tools, but it's a costly proposition.
The EUV camp has already spent billions on R&D. Development of "prototype" metrology tools alone is expected to add $200 million to the tally. Some estimate the total bill at $400 million. Sematech and its members, such as IBM, Intel, Samsung and TSMC, will foot some of the bill but are betting on metrology tool makers to share the cost and build the tools.
Some suggest that existing inspection tools could handle many of the initial chores in detecting EUV mask defects. "You probably only need [to build] an AIMS [aerial imaging metrology system] tool for high-volume manufacturing. Blank inspection and pattern inspection probably can be done with existing optical tools," said Yan Borodovsky, Intel senior fellow and director of advanced lithography at the company's Technology and Manufacturing Group.
But Sematech contends that current machines are not sensitive enough to detect defects in EUV masks. Some experts argue that the industry must develop actinic-based tools, with the same, 13.5-nm wavelength as EUV light.