Small Times
Oct. 5, 2006 — A team of engineers and technicians at International SEMATECH North have successfully used 193 nm immersion technology to pattern features narrower than 45 nm half-pitch in multiple orientations simultaneously.
The achievement was announced at the 3rd International Symposium on Immersion Lithography in Kyoto, Japan. SEMATECH North is part of the Albany NanoTech complex within the College of Nanoscale Science and Engineering of the University at Albany, NY.
The team used 193 nm immersion at 1.3 numerical aperture (NA) with azimuthal polarization, a technique which allows for aggressive imaging of arbitrary circuit features beyond simple line-and-space test patterns.
The team used an Exitech immersion projection microstepper with 1.3 NA in combination with optical proximity correction and other resolution enhancement techniques to simultaneously image sub-45 nm linewidths along X and Y axes within the same field. The resulting “pitch,” or width of a single line and its adjoining space, was 84 nm.
“Imaging at 84 nm pitch provides SEMATECH members with patterning capability beyond anything they are able to obtain on projection exposure tools today,” said Andrew Grenville, associate director of SEMATECH’s lithography division, in a prepared statement. “With this toolset, we are demonstrating feasibility that 193i can be used for 45 nm half-pitch manufacturing.”
Leading chip-makers currently are producing advanced semiconductors at 65 nm, with 45 nm manufacturing slated to begin volume production in 2010. Many lithographers consider 193 immersion the leading candidate for manufacturing at that technology level.
SEMATECH says it has a significant focus on understanding the ultimate limits of 193 nm lithography, especially with respect to high-index materials which may extend 193 immersion to 32 nm.
Preparing immersion lithography for manufacturing insertion is among SEMATECH’s top technology challenges, which also include development of infrastructure for photomasks and extreme ultraviolet (EUV) lithography.