The 193-nm question: How far can it go?

09/01/1997

The 193-nm question:How far can it go?

The question at the recent 193-nm Lithography Symposium in Japan was not whether 193 is coming, but how far it can be pushed, says Karen Brown, director of lithography at SEMATECH, Austin, TX, which began the series of meetings two years ago. The event was attended by over 380 people, with strong showings from the US, Europe, and Asia.

"Everyone wants to know how far they can push [193], because they don`t know what`s going to come after it," observes Brown. "Can we really find a robust process below 0.12-micron?"

One highlight was the presentation of imaged features as small as 90 nm (0.09 micron) by the Japanese ASET consortium, which has already begun working with phase-shift masks for improved resolution. "There was some collapse," at that level, Brown says, "but it`s still early days. They were showing really good imaging at 0.15, 0.14, 0.13."

Stepper companies were also in evidence, presenting design strategies, roadmaps, and timelines; reports indicate that the two Japanese suppliers, Nikon and Canon, are envisioning shipments somewhat behind those of SVG Lithography and ASM Lithography, but close enough to be reassuring to potential customers. "The designs are well along; they`re into making glass," commented Brown.

One more 193-nm conference will be held, in Austria in September 1998, said Brown. This is an extension of the original plan of three meetings; it came in response to a concern that another meeting would be needed to review progress on resists and exposure tools (which will not begin shipping until late 1998). "We just started this to facilitate 193 - not have another whole set of meetings," noted Brown. "Maybe by then it will be time to start another one for the next generation."

While 193 is virtually certain to arrive somewhere after the 0.18-micron generation of devices, its extendibility will be one of the central questions facing lithography developers. "Somewhere between 130 and 100 nm (0.13-0.10 micron) we will need the next generation," said Brown. The problem is that this post-193 transition will begin in just six years, and will almost certainly mark a significant paradigm shift. Device makers will thus demand earlier access to prototype tools to get enough experience to be secure with the new method.- P.N.D.