Momentum builds for directed self-assembly
3/2/2011 4:24 PM EST
Possible niche role
In the event that EUV cannot be made commercially viable, there are several other possibilities for future chip scaling, including DSA. But some say DSA and other technologies may have a future role even if EUV is put into volume production for high-end, mainstream logic chips.
"If self assembly comes to commercialization, there are some things it can do very well," said Eric Johnson, president of JSR Micro Inc., a unit of Japan's JSR Corp. Johnson suggested that DSA—which is potentially much less expensive than EUV production—could have applications in, for example, flash memory production, where the regular structure of circuits and cost sensitivity of the market may make it attractive.
JSR this week rolled out a DSA technology for the sub-20-nm half-pitch node that is being developed as part of an ongoing research agreement with IBM Corp. While most publicly known research into DSA utilizes block copolymer, JSA's technology uses a blend of polymers, giving it more stability and the capability to undergo wet etch processing, according to Hishiro.
DSA was a hit at last year's SPIE Advanced Lithography Conference, with more than 10 papers presented on the topic. This year there were significantly more, with some including Applied's Bencher suggesting the technology is moving from the lab to a more serious phase of commercial development.
"I'm really happy with the results we've gotten recently," said JSR's Johnson. "The recent progress is very encouraging."
In addition to Bencher's presentation, others at SPIE, including Joy Cheng of IBM, Hayato Namai of JSR Micro and Charlie Liu of the University of Wisconsin, detailed DSA research progress. Cheng highlighted improvements in process window and critical dimension uniformity in a project between IBM and the University of California-Santa Barbara.
Earlier in the day, Thomas Russell a processor at the University of Massachusetts—Amherst detailed extensive work on the challenges of using DSA to create measurably perfect structures. Russell highlighted several outstanding challenges and said there may be a fundamental limit on how small structures made with DSA can be built.
Russell also said that it may become more difficult to achieve etch contrast as the research moves to smaller structures and thinner films.
"I think that's going o be a synthetic challenge to utilizing some of the structures that I know we can provide," he said.