Tailored and Guided Dewetting of Block Copolymer/Homopolymer Blends

The dewetting and ordering characteristics of a lamellae-forming poly­(styrene-block-methyl methacrylate) block copolymer (BCP) either alone or blended with low-molecular-weight polystyrene and polymethylmethacrylate homopolymers were investigated. Although a significant reduction of the morphological stability is observed for the blend BCP compared to the neat BCP, an increase of 1 order of magnitude occurs in the correlation length of the lamellar nanodomains. Moreover, the morphological instability of the blend BCP results in dewetting of relatively thick films with the formation of micrometric-size areas consisting of highly ordered and defect-free perpendicular lamellar monodomains. These results can be exploited for large-scale manufacturing of BCP-based plasmonic and optical structures featuring substantial thickness modulation.