LONDON – European research institute IMEC (Leuven, Belgium) has co-developed a directed self-assembly (DSA) manufacturing process to improve both optical and extreme ultraviolet lithography
and installed a 300-mm compatible manufacturing line within its pilot fab . The organization is expected to announce details of the successful implementation of DSA at the SPIE advanced lithography conference taking place in San Jose, California Feb., 12 to 16.
DSA makes use of natural processes within materials to produce ordered structures. Some of these processes such as the formation of stripes within polymeric materials can be fined tuned by altering the chemistry to achieve nanometric features that can be used to augment optical and extreme ultra-violet lithography.
The upgrade of an academic lab-scale DSA process flow to a fab-compatible flow was realized in collaboration with the University of Wisconsin, AZ Electronic Materials and Tokyo Electron Ltd. The collaboration aims to take DSA through to high-volume manufacturing.
Directed Self-Assembly (DSA) is gaining momentum as a means for extending optical lithography beyond its current limits. DSA is an alternative patterning technology that enables frequency multiplication through the use of block copolymers. When used in conjunction with an appropriate pre-pattern that directs the orientation for patterning, DSA can reduce the pitch of the final printed structure. Moreover, DSA can be used to repair defects and repair uniformity in the original print.
The repair feature is particularly useful when used in combination with EUV lithography, which is characterized by local variation in critical dimensions.
Figure shows 14-nm polystyrene lines on 28-nm pitch after PMMA removal fabricated by DSA using 193-nm immersion lithography based on a 84-nm pitch pre-pattern (left) and demonstration of the ability to repair a 200-nm gap in the pre-pattern (right). Source: IMEC.
IMEC now has a DSA coater/developer from Tokyo Electron and DSA materials along with pattern transfer and metrology system in the cleanroom ready for chipmakers. The same clean room contains 248-nm 193-nm optical wavelength scanners in both dry and immersion formats together with an EUV lithography machine.
"The availability of a DSA processing line enables us to further push the limits of 193nm immersion lithography and overcome some of the critical concerns for EUV lithography. This allows us to further push the limits of Moore’s law," said Kurt Ronse, director of lithography at IMEC, in a statement.
In the same statement Professor Paul Nealey of the University of Wisconsin said: "Juan de Pablo and I and the University of Wisconsin team are very pleased to have the opportunity to partner with IMEC. Our work together results in unprecedented integration of DSA with manufacturing-ready tools and materials, allows investigation of the ultimate potential and possible limits of DSA not possible in an academic setting, and provides exceptional educational opportunities for our students. We are gratified to be on a pathway with IMEC towards commercialization of technology we have spent almost 15 years developing."
IMEC is offering access to, and participation in, DSA research as part of its core CMOS program, which includes Globalfoundries, Intel, Micron, Panasonic, Samsung, TSMC, Elpida, Hynix, Fujitsu and Sony as participants.Related links and articles:
SPIE Advanced Lithography 2012
Applied, Stanford demo copolymer litho
IBM, JSR roll out self-assembly litho
Momentum builds for directed self-assembly
Directed self-assembly grabs the spotlight at SPIE