VELDHOVEN, The Netherlands ASML didn't even mention the acronym EUV in formal presentations to international press here a year ago. This year they showed the same group a rough road map for extreme ultraviolet lithography systems that could be ready for commercial use in late 2012.
In October 2008, ASML was still constructing the massive clean room where it would build its first EUV systems that it expects to take the art of chip making to an 11-nanometer node someday. Today at least five chip makers have ordered ASML's first EUV system being built there, the NXE 3100 characterized as a pre-production tool.
An analyst speculated Hynix, IMEC, Intel, Samsung, Toshiba and possibly TSMC are the initial customers for the NXE 3100. But one system will probably also go to the Albany research center that along with IMEC received the first prototype tool.
The 3100 will largely be an R&D vehicle for chip makers and their third party suppliers. It aims to put out about 60 wafers/hour. That's a fraction of the nearly 200 wafers/hour potential of today's best immersion lithography systems.
For systems shipping in 2015 or later, "we are targeting about 180 wafers/hour, which is very aggressive," said Ron Kool who manages ASML's EUV program.
The chief challenge is getting power to the wafer.
The 13.5 nm wavelength light sources used in EUV systems are far below the power levels of the 193nm argon fluoride light sources in today's immersion litho systems. As a result the prototype EUV tool at the IMEC research center in nearby Leuven, Belgium, has produced features in the range of 20nm, but only a few wafers per hour.
Philips supplied the 20W light source in the alpha tool used at IMEC and the U.S. research center in Albany, New York. Cymer is supplying a 75W light source that should scale to 100W for the 3100 system shipping next year.
The key combination of light source and optics is expected to evolve over the first few generations of EUV systems. It represents the hardest of several difficult challenges with the new litho systems.
The Cymer light source is created by the synchronized collision of drops of liquid tin and bursts of carbon-dioxide laser light. The result is a plasma easily absorbed by impurities in the ambient air.
"That means the mirror optics and moving stages and the whole light path must be operated inside a vacuum," said Kool.
Inside that vacuum, engineers need to steer the 13.5nm light through an array of focusing mirrors with the equivalent accuracy of a flashlight beam hitting a penny on the surface of the moon. To maintain that accuracy the mirrors need to be extremely flat, varying no more than the equivalent of a millimeter every 1,000 miles.
"This is like putting a man on the moon," said one veteran editor in the audience.