Chemically directed self-assembly of perpendicularly aligned cylinders by a liquid crystalline block copolymer

Abstract

Chemical epitaxy with a density multiplication process was applied to the perpendicularly oriented hexagonal cylinder nanostructure of liquid crystalline block copolymer (PEO-b-PMA(Az)) thin film through thermally induced microphase separation by using a newly designed PMA(Az)₂₄ brush. The hexagonal lattice orientation with 1.9 tera-cylinders per inch² was laterally controlled for long-range-ordered direct self-assembly. Furthermore, the direct pattern-transfer of the assembled structure to an Au nanodot array was demonstrated by doping of HAuCl₄ selectively into the PEO cylindrical microdomains and then vacuum ultraviolet light irradiation to cause polymer etching and reduction of the Au ions.