Report

Polarity-Switching Top Coats Enable Orientation of Sub–10-nm Block Copolymer Domains

Science  09 Nov 2012:
Vol. 338, Issue 6108, pp. 775-779
DOI: 10.1126/science.1226046

You are currently viewing the abstract.

View Full Text

Via your Institution

Log in through your institution

Log in through your institution


Abstract

Block copolymers (BCPs) must necessarily have high interaction parameters (χ), a fundamental measure of block incompatibility, to self-assemble into sub–10-nanometer features. Unfortunately, a high χ often results from blocks that have disparate interfacial energies, which makes the formation of useful thin-film domain orientations challenging. To mitigate interfacial forces, polymers composed of maleic anhydride and two other components have been designed as top coats that can be spin-coated from basic aqueous solution in the ring-opened, acid salt form. When baked, the anhydride reforms and switches polarity to create a neutral layer enabling BCP feature alignment not possible by thermal annealing alone. Top coats were applied to the lamella-forming block copolymers poly(styrene-block-trimethylsilylstyrene-block-styrene) and poly(trimethylsilylstyrene-block-lactide), which were thermally annealed to produce perpendicular features with linewidths of 15 and 9 nanometers, respectively.

View Full Text