By J. Robert Lineback, M. David Levenson, Senior Editors, Solid State Technology magazine

With no ‘showstoppers’ identified yet in immersion lithography, rival scanner makers ASML, Canon, and Nikon are accelerating efforts to take 193nm ‘wet’ exposure tools to the next level, quickly pushing numerical aperture (NA) lenses to their feasible limits in systems using water to boost depth of focus and resolution for 65nm and 45nm processes. All three say they now plan to launch high-volume immersion scanners with ‘hyper-NA’ optics – up to and slightly over 1.3 NA – between 2Q06 and January 2007.

To go beyond that, researchers and material suppliers are beginning to narrow the options for high-index immersion fluids, which will eventually replace water and support next-generation ArF lithography with lens systems in the 1.5-1.6 NA range for 32nm and beyond process nodes.

“It is now conceivable that some version of ArF could lead down to 20nm half-pitch,” said Gene Fuller, principal engineer for Nikon Precision Inc., during a panel discussion held in conjunction with SPIE’s 30th International Symposium on Microlithography (Feb. 28-March 4) in San Jose, CA.