Xuanxuan Chen, Chun Zhou, Shuang-Jun Chen, Gordon S W Craig, Paulina Rincon-Delgadillo, Takahiro Dazai, Ken Miyagi, Takaya Maehashi, Akiyoshi Yamazaki, Roel Gronheid, Mark Stoykovich, Paul F Nealey
Polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) is one of the prototypical block copolymers (BCPs) in directed self-assembly (DSA) research and development, with standardized protocols in place for processing on industrially relevant 300 mm wafers. Scaling of DSA patterns to pitches below 20 nm using PS-b-PMMA, however, is hindered by the relatively low Flory-Huggins interaction parameter,χ. Here we investigate the approach of adding small amounts of ionic liquids (IL) into PS-b-PMMA, which selectively segregates into the PMMA domain and effectively increases the χ parameter and thus the pattern resolution...
April 18, 2018: ACS Applied Materials & Interfaces