Bending Behavior and Directed Self-Assembly of Rod-Coil Block Copolymers.

The formation of zigzags, chevrons, Y-junctions, and line segments is demonstrated in thin films formed from cylindrical morphology silicon-containing conformationally asymmetric rod-coil diblock copolymers and triblock terpolymers under solvent annealing. Directed self-assembly of the block copolymers within trenches yields well-ordered cylindrical microdomains oriented either parallel or transverse to the sidewalls depending on the chemical functionalization of the sidewalls, and the location and structure of concentric bends in the cylinders is determined by the shape of the trenches. The innate etching contrast, the spontaneous sharp bends and junctions, and the range of demonstrated periodicity and line/space ratios make these conformationally asymmetric rod-coil polymers attractive for nanoscale pattern generation.