Shui Tian-En, Chang Tongxin, Wang Zhe, Huang Haiying
College of Materials Science and Engineering, Changchun University of Technology, Changchun 130012, China.
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Polymers (Basel). 2025 May 2;17(9):1242. doi: 10.3390/polym17091242.
Block copolymer (BCP) lithography is widely regarded as a promising next-generation nanolithography technique. However, achieving rapid assembly with defect-free morphology remains a significant challenge for its practical application. In this study, we presented a facile and efficient solvent annealing method for fabricating well-ordered BCP thin films within minutes on both flat and topographically patterned substrates. By accelerating the swelling process, rapid film swelling was observed within just 10 s of annealing, leading to well-ordered morphologies in 1~3 min. Furthermore, we systematically investigated the influence of swelling ratio (SR) on film morphology by precisely tuning solvent vapor pressure. For cylinder-forming poly(styrene-block-2-vinylpyridine) (PS-b-P2VP) films, we identified three distinct SR-dependent ordering regimes: (I) Excessive SR led to a disordered morphology; (II) near-optimal SR balanced long-range and short-range orders, and a slight increase in SR enhanced the long-range order but introduced short-range defects. (III) Insufficient SR failed to provide adequate chain mobility, limiting long-range order development. These findings highlight the critical role of SR in controlling defect density in nanopatterned surfaces. Long-range-ordered BCP nanopatterns can only be achieved under optimal SR conditions that ensure sufficient chain mobility. We believe this rapid annealing strategy, which is also applicable to other solvent-based annealing systems for BCP films, may contribute to next-generation nanolithography for microfabrication.
嵌段共聚物（BCP）光刻技术被广泛认为是一种很有前途的下一代纳米光刻技术。然而，实现具有无缺陷形态的快速组装对于其实际应用仍然是一个重大挑战。在本研究中，我们提出了一种简便高效的溶剂退火方法，可在几分钟内在平坦和具有拓扑图案的基板上制备出有序的BCP薄膜。通过加速溶胀过程，在退火仅10秒内就观察到薄膜快速溶胀，在1至3分钟内形成了有序的形态。此外，我们通过精确调节溶剂蒸气压系统地研究了溶胀率（SR）对薄膜形态的影响。对于形成柱状的聚（苯乙烯 - 嵌段 - 2 - 乙烯基吡啶）（PS-b-P2VP）薄膜，我们确定了三种不同的依赖于SR的有序状态：（I）过高的SR导致无序形态；（II）接近最佳的SR平衡了长程和短程有序，SR的轻微增加增强了长程有序，但引入了短程缺陷。（III）不足的SR未能提供足够的链迁移率，限制了长程有序的发展。这些发现突出了SR在控制纳米图案表面缺陷密度方面的关键作用。只有在确保足够链迁移率的最佳SR条件下才能实现长程有序的BCP纳米图案。我们相信这种快速退火策略，也适用于其他用于BCP薄膜的基于溶剂的退火系统，可能有助于下一代微纳加工纳米光刻技术的发展。
