Jung Hyunjung, Woo Sanghoon, Park Sungmin, Lee Sumi, Kang Minhyuk, Choe Youngson, Son Jeong Gon, Ryu Du Yeol, Huh June, Bang Joona
Department of Chemical and Biological Engineering, Korea University, Seoul 136-713, Republic of Korea.
Soft Matter. 2015 Jun 7;11(21):4242-50. doi: 10.1039/c5sm00250h.
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.
由于嵌段共聚物（BCP）微区有序排列的尺度约为10纳米、可获得的微结构种类多样及其与当前光刻工艺的兼容性，嵌段共聚物的定向自组装（DSA）已成为一种替代或补充传统光刻技术的方法。在DSA中，BCP微区通过导向图案进行控制，两种主要技术较为流行：图形外延和化学外延组装。我们通过将图形外延与“廉价的”化学外延组装相结合，展示了一种用于DSA工艺的简单可行技术，以改善层状微区的排列。对于化学外延组装，来自可交联的、形成圆柱的BCP的六边形表面图案被用于引导上层BCP层状膜的图形外延组装。当在六边形图案上制备导向图案时，发现与均匀中性层上的层状排列相比，层状排列程度得到显著改善。模拟结果表明，底层的六边形图案可以通过减少层状层的大量取向状态来辅助层状排列。该策略适用于各种需要在大面积上以降低成本高度精确地控制纳米图案的纳米制造工艺。
