TAIPEI, Taiwan While semiconductor industry officials in California upped the ante for advanced IC production technology with the rollout of the 2001 International Technology Roadmap for Semiconductors on Thursday (Nov. 29), a gathering of mostly U.S.-based researchers warned a group of Taiwanese chip manufacturers that numerous obstacles jeopardize a smooth transition to implementing 157-nanometer lithography.
During a two-day forum here on issues associated with 157-nanometer lithography technology, speakers from International Sematech, IBM, ASML and other organizations detailed the challenges to realizing volume or even pilot manufacturing using 157-nanometer tools.
The hurdles prompted a Sematech official to caution that a rollout of 157-nanometer tools and materials by 2003 is likely an unreasonable target. "There's a very low probability that that will happen," said Chris Van Peski, a senior member of the Advanced Optical Development staff at Sematech. "Now will someone have a tool and be producing wafers? Probably so. But it would be stretched to say that it would be a true piloting start," he said.
The 2001 International Technology Roadmap for Semiconductors rolled out by chip industry officials in Santa Clara, Calif. on Thursday accelerated by about one year earlier assumptions of progress on main technology nodes. For the ITRS' near-term goals, 100-nanometer and 70-nanometer process technology will be able to use 193-nanometer lithography, which is currently in test and in need of refinement. But Sematech's own objectives call for pilot starts using 157-nanometer lithography at the 100-nanometer (0.10-micron) process node within two years and for manufacturing starts at 70 nanometer (0.07 micron) by 2005.
"That is a very aggressive schedule," Van Peski said. "The transition to 193 was significantly different than the transition to 157. The requirements were just not nearly as challenging. So we don't really have the experience to look back on. There are a lot of red lights that need to be dealt with."
Potential show stoppers
Still among the critical issues and potential show stoppers that were discussed are problems associated with photo resists, availability of calcium fluoride for lens manufacturing and the contamination of optical elements.
A half-dozen commercial suppliers are developing resists for the 157-nanometer node and several universities have also joined the effort. Progress is being made, but not enough to satisfy the Sematech timeline currently in place, said Scott MacDonald, an IBM researcher and visiting senior scientist in the Department of Chemical Engineering at the University of Texas at Austin.
"There are a lot of people doing research and working very hard, but things clearly are at the research stage, where you have graduate students making 3 or 5 grams of material, which is not production quantity," he said. "It takes a long time to go from lab to production-worthy material and that's a very aggressive timeline that Sematech is marching toward."
Next month, Sematech will host a technical data review in Florida for 157-nanometer technology, during which researchers will reevaluate the progress on critical obstacles. "All aspects of the technology must be ready for the introduction," Van Peski warned. "Significant delays could decrease the economic viability of 157-nanometer technology."