Soft Graphoepitaxy of Block Copolymer Assembly with Disposable Photoresist Confinement

We demonstrate soft graphoepitaxy of block copolymer assembly as a facile, scalable nanolithography for highly ordered sub-30-nm scale features. Various morphologies of hierarchical block copolymer assembly were achieved by means of disposable topographic confinement of photoresist pattern. Unlike usual graphoepitaxy, soft graphoepitaxy generates the functional nanostructures of metal and semiconductor nanowire arrays without any trace of structure-directing topographic pattern. Our novel approach is potentially advantageous for multilayer overlay processing required for complex device architectures. Various nanolithographic technologies such as e-beam lithography, scanning probe lithography, and nanoimprinting have been explored to overcome the resolution limit of conventional photolithography. Nonetheless, the low through-put of the serial writing process or technical barriers arising from mechanical contact obstructs a large-area production of densely packed nanostructures.1-3 Directed self-assembly of block copolymers is considered a promising alternative that may overcome those limitations.4-18 The spontaneou