Directed self-assembly of block copolymer films on atomically-thin graphene chemical patterns

• Published in: Scientific reports 2016-08, Vol.6 (1), p.31407-31407, Article 31407
• Main Authors: Chang, Tzu-Hsuan, Xiong, Shisheng, Jacobberger, Robert M., Mikael, Solomon, Suh, Hyo Seon, Liu, Chi-Chun, Geng, Dalong, Wang, Xudong, Arnold, Michael S., Ma, Zhenqiang, Nealey, Paul F.
• Format: Article
• Language: English
• Subjects: 639/301/357/1018; 639/301/923/1028; 639/301/923/966; 639/638/298/917; 639/925/930/543; Copolymers; Germanium; Humanities and Social Sciences; Kinetics; MATERIALS SCIENCE; multidisciplinary; Polymers; Polystyrene; Science; Self-assembly; Topography
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep31407

Directed self-assembly of block copolymers is a scalable method to fabricate well-ordered patterns over the wafer scale with feature sizes below the resolution of conventional lithography. Typically, lithographically-defined prepatterns with varying chemical contrast are used to rationally guide the assembly of block copolymers. The directed self-assembly to obtain accurate registration and alignment is largely influenced by the assembly kinetics. Furthermore, a considerably broad processing window is favored for industrial manufacturing. Using an atomically-thin layer of graphene on germanium, after two simple processing steps, we create a novel chemical pattern to direct the assembly of polystyrene-block-poly(methyl methacrylate). Faster assembly kinetics are observed on graphene/germanium chemical patterns than on conventional chemical patterns based on polymer mats and brushes. This new chemical pattern allows for assembly on a wide range of guiding periods and along designed 90° bending structures. We also achieve density multiplication by a factor of 10, greatly enhancing the pattern resolution. The rapid assembly kinetics, minimal topography and broad processing window demonstrate the advantages of inorganic chemical patterns composed of hard surfaces.