WHAT: Extreme Ultraviolet Engineering Test Stand
WHERE: Sandia National Laboratories/Livermore, California
WHO: Virtual National Laboratory, with funding from the Extreme Ultraviolet Limited Liability Company, an industry consortium of microchip manufacturers.
WHY: To develop and test extreme ultraviolet lithography (EUVL) techniques, with which chip makers hope to overcome the limitations of current production methods. The optical lithography used to create the 250-nanometer circuit patterns on today's microprocessors can't carve features smaller than 100 nm; the wavelength needed for such intricate details would be absorbed rather than refracted by the equipment's quartz lens. To extend Moore's law beyond 2007, the industry must find new ways to shrink circuitry for greater speed and efficiency.
HOW: Like today's optical lithography, EUVL shines light onto a silicon wafer treated with photosensitive resin; the photons create a circuit pattern. The Engineering Test Stand, the first full-scale EUVL prototype, replaces the conventional lens with mirrors that can direct light of even the shortest wavelengths. One mirror reflects light from the source onto a reflective mask, the stencil that defines the pattern of the circuits. The photons bounce off the mask and then through a series of four high-precision mirrors - each coated with 81 layers of reflective molybdenum and silicon films - which incrementally reduce the image and cast it onto the wafer. The test stand has produced features as small as 80 nm, and a six-mirror system now in development could go even smaller. A production model should be ready in five years.
