Soft-Shear-Aligned Vertically Oriented Lamellar Block Copolymers for Template-Free Sub-10 nm Patterning and Hybrid Nanostructures
Maninderjeet Singh, Aman Agrawal, Wenjie Wu, Ali Masud, Edward Armijo, Damian Gonzalez, Shenghui Zhou, Tanguy Terlier, Chenhui Zhu, Joseph Strzalka, Krzysztof Matyjaszewski, Michael R. Bockstaller, Jack F. Douglas, Alamgir Karim
Abstract
The template-free unidirectional alignment of lamellar block copolymers (l-BCPs) for sub-10 nm high-resolution patterning and hybrid multicomponent nanostructures is important for technological applications. We demonstrate a modified soft-shear-directed self-assembly (SDSA) approach for aligning pristine l-BCPs and l-BCPs with incorporated polymer-grafted nanoparticles (PGNPs), as well as the l-BCP conversion to aligned gold nanowires, and hybrid of metallic gold nanowire and dielectric silica nanoparticle in the form of line-dot nanostructures. The smallest patterns have a half-pitch as small as 9.8 nm. In all cases, soft-shear is achieved using a high-molecular-mass polymer topcoat layer, with support on a neutral bottom layer. We also show that the hybrid line-dot nanostructures have a red-shifted plasmonic response in comparison to neat gold nanowires. These template-free aligned BCPs and nanowires have potential use in nanopatterning applications, and the line-dot nanostructures should be useful in the sensing of biomolecules and other molecular species based on the plasmonic response of the nanowires.