Enhanced self-assembly of block copolymers by surface modification of a guiding template

• Published in: Polymer journal Vol. 50; no. 2; pp. 221 - 229
• Main Authors: Park, Woon Ik, Choi, Young Joong, Yuk, Jong Min, Seo, Hyeon Kook, Kim, Kwang Ho
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.02.2018; Nature Publishing Group
• Subjects: 639/301/923/1028; 639/301/923/966; Annealing; Biomaterials; Bioorganic Chemistry; Block copolymers; Brush plating; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Electron microscopy; Original Article; Polydimethylsiloxane; Polymer Sciences; Polystyrene resins; Self-assembly; Silicone resins; Surfaces and Interfaces; Thin Films
• ISSN: 0032-3896; 1349-0540
• DOI: 10.1038/s41428-017-0007-5

The formation of highly ordered patterns of block copolymers (BCPs) with high χ is important for next-generation lithography applications. We demonstrate here a surface-engineering methodology to enhance the self-assembly of poly(styrene- b -dimethylsiloxane) (PS- b -PDMS) BCPs with high χ by employing a hydroxyl-terminated polystyrene (PS-OH) brush. By precisely controlling the molecular weight (MW) and weight percent of PS-OH, well-ordered sub-20-nm BCP patterns were obtained over a large area in a short annealing time (<10 min) with the use of guiding templates. We systemically analyzed how the PS-OH brush affects the self-assembly kinetics of BCPs with various MWs and volume fractions. Moreover, the transmission electron microscopy (TEM) results strongly support that the PS-modulated surface plays an important role in the ordering of BCP patterns. We also achieved well-aligned 12 nm line and 18 nm dot patterns within 3 min by means of binary solvent vapor annealing at a moderate temperature under the optimum PS-OH brush conditions. These results provide a new platform for effective engineering and manipulation of the self-assembly of other BCPs for advanced BCP nanotechnologies. A facile and practical surface-engineering methodology to enhance the self-assembly of PS- b -PDMS BCPs with high χ by precisely controlling the molecular weight and weight percent of PS brushes. Highly ordered sub-20-nm BCP patterns were successfully obtained in a few minutes under the optimum PS brush condition.