Lattice-Matched Self-Directed Assembly of Diblock Copolymer Thin Films for a Large Area Quasi-Single-Crystal 2D Dot Array

Abstract

The creation of dense periodic nanostructures using block copolymer (BCP) thin films is often struggled due to the formation of inherent defects and a short-ranged orientation, which act as obstacles to the successful application of BCP nanopatterning. While directed self-assembly (DSA) has substantially improved the structural order and controllability of pattern orientation, the quality of nanofabrication through the DSA is below the industrial expectations. Here, we suggest a facile method to create a quasi-single-crystalline 2D hexagonal array while conserving the pattern orientation along the controlled direction over a centimeter-scale area. The arrays are formed during the solvent vapor annealing (SVA) driven morphology transition from shear-aligned BCP cylinders to spheres where the SVA resolves the lattice-mismatching. The grazing small angle X-ray scattering and image analysis were performed to elucidate underlying mechanism and the superior performance of this strategy.