Jeong Jiyoung, Ha Jeong Sook, Lee Sang-Soo, Son Jeong Gon
Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology, 14 gil-5 Hwarangno, Seongbuk-gu, Seoul, 136-791, Republic of Korea.
KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 136-701, Republic of Korea.
Macromol Rapid Commun. 2015 Jul;36(13):1261-6. doi: 10.1002/marc.201500088. Epub 2015 Apr 13.
Highly ordered perpendicular orientation and straightly parallel orientation coexisting polystyrene-block-polydimethylsiloxane (PS-b-PDMS) cylindrical microdomains with 10 nm width can be realized by using polyvinyl acetate as a partially dewetted topcoat and solvent annealing with acetone vapor. During solvent annealing, the swelled topcoat begins to dewet and the dewetting rim sweeps the surface of the block copolymer films to align the cylindrical microdomains with the direction of dewetting propagation. However, the wetted region of the topcoat/PS-b-PDMS film forms with a perpendicular orientation due to reduced surface tension and sufficient concentration gradient in the solvent evaporation step. The orientational changes (perpendicular/straightly parallel orientation) in the dewetted/wetted area are also investigated according to the vapor pressure of solvent annealing. The degree of directionality of the swept PS-b-PDMS films according to the distance from the dewetting front, which is equivalent with time after sweeping, is examined. To control the direction of dewetting and complex structures within a specific area, an imprinting process is introduced to form topographical line-space patterns in the topcoat and perpendicular/parallel orientation of BCP patterns in the line-space patterns, respectively.
通过使用聚醋酸乙烯酯作为部分去湿的面漆并进行丙酮蒸汽溶剂退火，可以实现具有10纳米宽度的高度有序的垂直取向和直线平行取向共存的聚苯乙烯-嵌段-聚二甲基硅氧烷（PS-b-PDMS）圆柱形微区。在溶剂退火过程中，溶胀的面漆开始去湿，去湿边缘扫过嵌段共聚物薄膜表面，使圆柱形微区沿去湿传播方向排列。然而，由于在溶剂蒸发步骤中表面张力降低和浓度梯度足够，面漆/PS-b-PDMS薄膜的湿润区域形成垂直取向。还根据溶剂退火的蒸气压研究了去湿/湿润区域的取向变化（垂直/直线平行取向）。研究了根据与去湿前沿的距离（等同于扫过后的时间），扫过的PS-b-PDMS薄膜的方向性程度。为了控制特定区域内的去湿方向和复杂结构，引入了压印工艺，分别在面漆中形成形貌线间距图案，并在线间距图案中形成BCP图案的垂直/平行取向。
