Orientation control of organic supramolecular columns by high resolution guiding patterns

Abstract

In this study, we investigate the orientation control of the organic supramolecular columns, which form the hexagonally aligned cylindrical nanostructures with 4.75 nm diameter, using high resolution guiding patterns. By the bottom-up lithography based on block copolymers, the guiding patterns were fabricated with small pattern width (< 50 nm), which is much smaller than that of conventional guiding patterns fabricated by top-down lithography (> 1000 nm). Characterized by atomic force microscopy (AFM), we confirm that high resolution guiding patterns can control the orientation of the supramolecular columns into parallel or perpendicular to the pattern axis by the variation of the film thickness. Due to strong guiding effect from high resolution patterns, the alignment in the curved patterns exhibited improved bending morphology relative to that of previous work. In combination with the directed self-assembly of block copolymers, these high resolution guiding patterns are expected to be the method for unidirectional nanopatterns over a large area, nanostructures formation with complex geometries for various applications, and orientation control with long-range lateral order above the patterned area.