Nuclear fusion research aids EUV source breakthrough
7/5/2012 10:40 AM EDT
LONDON – A University of Washington laboratory that has been working for more than a decade on nuclear fusion as a source of energy, thinks it has leapfrogged ahead of companies trying to create a viable light source for extreme ultraviolet lithography (EUV).
Zplasma Inc. (Seattle, Wash.) will be competing with such firms as Cymer Inc., Xtreme Technologies GmbH and Gigaophoton Inc. but reckons that with a 1,000 times improvement in output energy it can easily provide the source power to make EUV lithography machine throughputs viable.
The principle methods used currently are discharged-produced or laser produced plasmas of xenon or tin (DPP or LPP) but both consume large amounts of energy. More importantly neither has reached the 100- or 200-watts power level at the intermediate focus needed to get 60 to 125 wafers per hour throughput from a EUV lithography machine, such as the NXE:3300B from ASML Holding NV (Veldhoven, The Netherlands).
"We're able to produce that light with enough power that it can be used to manufacture microchips," said Uri Shumlak, a UoW professor of aeronautics and astronautics, in a report on the University of Washington website.
Click on image to enlarge.
The University of Washington nuclear fusion lab includes a tank containing plasma for energy research as well as a smaller system for electronics applications. Source: University of Washington
As with other 13.5-nm wavelength light sources, the UoW beam is based on a plasma (xenon). And the UoW fusion lab's specialty is lower-cost versions of a fusion reactor, which uses electric current rather than magnets to contain the plasma and which produces plasma that is stable and long-lived.
This has advantages over a discharge spark propagated through a tin vapor or shooting a laser at a tin droplet, the group claims. "It's a completely different way to make the plasma that gives you much more control," said Brian Nelson, a UW research associate professor of electrical engineering, in the website report.
The alternative EUV light sources produce a pulse of light that lasts between 20 and 50 microseconds The Zplasma light source lasts about 1,000 times longer and this results in more light output, and more light onto the wafer. The UoW team has been supported with grants and gifts to allow them to verify the production of 13.5-nm wavelength light and to reduce the size of the equipment.
The company is now led by Henry Berg, a technology entrepreneur, as CEO. The company is now seeking venture capital from corporate investors who can help Zplasma integrate its light sources with existing industrial processes.