Rapid Self-Assembly and Sequential Infiltration Synthesis of High χ Fluorine-Containing Block Copolymers
Cian Cummins, Daniele Mantione, Federico Cruciani, Guillaume Pino, Nils Demazy, Yulin Shi, Giuseppe Portale, Georges Hadziioannou, Guillaume Fleury
Abstract
We leverage the attractive properties of a high χ–low N BCP, i.e., poly(styrene)-block-poly(2-fluoroethylmethyl acrylate) (PS-b-P2FEMA), and illustrate its utility for next-generation nanomanufacturing. The synthesis, physical characterization, and thin film self-assembly of a series of lamellar and cylindrical PS-b-P2FEMA BCPs are delineated. PS-b-P2FEMA BCPs with total molecular weights ranging from 7 to 22 kg mol–1 were synthesized by using reversible addition–fragmentation chain-transfer (RAFT) polymerization. Temperature-resolved small-angle X-ray scattering (SAXS) measurements revealed a large χ value (0.13 at 150 °C) for PS-b-P2FEMA. Solvothermal vapor annealing of PS-b-P2FEMA films produced highly oriented fingerprint patterns in as short as 60 s. Lamellar period sizes ranged from 25.9 down to 14.2 nm with feature sizes as small as 7 nm observed. We also demonstrate the integration feasibility of PS-b-P2FEMA BCPs through alumina hardmask formation using sequential infiltration synthesis. The highly favorable characteristics of the P2FEMA-based BCPs detailed here provide a versatile material option to the current library of available BCPs for sub-10 nm nanolithography.