Synthesis and directed self-assembly of modified PS-b-PMMA for sub-10 nm nanolithography

The directed self-assembly (DSA) of block copolymers has attracted a great deal of interest due to its potential applications in sub-10 nm lithography [1–3]. The conventional organic-organic DSA materials such as poly-(styrene-block-methyl methacrylate) (PS-b-PMMA) have been extensively studied [4,5], however, the low etch contrast between two blocks and the difficulty to reduce L0 limit its application. In this study, we designed and synthesized the novel DSA materials based on PS-b-PMMA. Through the modifying of acrylics part, segment-segment interaction parameter (χ) can be significantly increased, which leads to rapid self-assembly and high etch contrast.