title: Combined epitaxial self-assembly of block copolymer lamellae on a hexagonal pre-pattern within microgrooves.
abstract: The directed self-assembly (DSA) of block copolymers (BCPs) has emerged as an alternative method to replace or complement conventional photolithography as a result of the approximately 10 nm scale of microdomain ordering, the variety of microstructures that can be obtained and its compatibility with current lithographic processes. In DSA, BCP microdomains are controlled via guide patterns and two main techniques are popular: graphoepitaxy and chemoepitaxy assembly. We have demonstrated a simple and feasible technology for a DSA process by combining graphoepitaxy with "inexpensive" chemoepitaxial assembly to improve the alignment of the lamellar microdomains. For chemoepitaxial assembly, the hexagonal surface patterns from cross-linkable, cylinder-forming BCP were used to guide the graphoepitaxial assembly of the overlying BCP lamellar film. When the guiding patterns were prepared on the hexagonal patterns, it was found that the degree of lamellar alignment was significantly improved compared with the lamellar alignment on the homogeneous neutral layers. Simulation results suggested that the underlying hexagonal pattern can assist the lamellar alignment by reducing the large number of orientation states of the lamellar layers. This strategy is applicable to various nanofabrication processes that require a high degree of fidelity in controlling the nanopatterns over large areas with reduced costs.
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul 136-713, Republic of Korea. junehuh@korea.ac.kr joona@korea.ac.kr.
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Jung
authors.forename: Sanghoon
authors.initials: S
authors.lastname: Woo
authors.forename: Sungmin
authors.initials: S
authors.lastname: Park
authors.forename: Sumi
authors.initials: S
authors.lastname: Lee
authors.forename: Minhyuk
authors.initials: M
authors.lastname: Kang
authors.forename: Youngson
authors.initials: Y
authors.lastname: Choe
authors.forename: Jeong Gon
authors.initials: JG
authors.lastname: Son
authors.forename: Du Yeol
authors.initials: du Y
authors.lastname: Ryu
authors.forename: June
authors.initials: J
authors.lastname: Huh
authors.forename: Joona
authors.initials: J
authors.lastname: Bang