Hierarchical self-assembly of block copolymers for lithography-free nanopatterning

A study was conducted to demonstrate a hierarchical nanopatterning process, using self-assembling block copolymers. It was demonstrated that the microscale architecture in a block-copolymer film directed the spontaneous alignment of the nanoscale morphology through the directional growth of well-ordered domains. It was also demonstrated that the facile and robust nanopatterning process, employing the two levels of spontaneous orderings, represents a versatile pathway to control nanoscale morphology, by manipulating microscale architecture. It was observed that the approach was readily applicable to an arbitrarily large area, due to the simplicity of the microscale patterning process. The study also demonstrated that the shape and characteristic length scales of microscale pattern can be easily tuned with other noninvasive patterning techniques through the approach.