| Directed self-assembly with block copolymers (BCP) is an emerging method to form high-resolution, periodic nanostructures for applications including: nanoelectronics, membranes/filtrations, bit-patterned media, to protein immobilization. BCPs can self-assemble into a dense, periodic array of nanostructures such as spheres, cylinders, and lamellae with feature sizes of three to hundreds of nanometers. In contrast to conventional methods such as electron-beam lithography, BCP lithography is a low cost, scalable, high throughput method. New low molecular weight BCPs with highly incompatible blocks (known as high-chi BCPs) are being developed for accessing single nanometer feature sizes. In addition, the emergence of new materials such as graphene, transitional metal dichalogenides, and black phosphorus, have led to interesting scientific and technological discoveries when these materials are patterned or confined in the nanometer regime. The work presented in this thesis addresses many of the challenges in the assembly of emerging functional BCPs and pattern transferring at small-length scales using BCP lithography. These challenges include: 1) nanopatterning substrates other than silicon, like graphene, 2) pattern transferring from self-assembled thin-films in sub-10 nm length scales, and 3) moving beyond passive pattern transfer applications into reactive coatings. In the first part of this thesis, we fabricate semiconducting graphene through BCP lithography. These studies introduce new ways for patterning unconventional surfaces while preserving the materials' unique electrical properties. Second, we detail an effective method to enhance etch selectivity of a new cylinder-forming self-assembled high-chi BCP by exposing a metal vapor precursor to selectively coordinate and react with a polymer domain, thereby creating an inorganic hard mask for pattern transfer in the sub-10 nm regime. Finally, we examine the thin-film assembly and functionalization of a reactive cylinder-forming BCP. A solvent annealing method is developed to drive microphase separation and to control the microdomain orientation in thin-film. We also demonstrate two methods of BCP functionalization: first method involves tagging the reactive domains with a primary amine commonly used for protein immobilization; second method involves the incorporation of a metal vapor precursor into the reactive domains to create alumina nanowires and nanodots are explored. |
