Wu Zhiyong, Luo Jiacheng, Li Luyang, Dong Qingshu, Zhang Xiaohui, Li Zili, Liu Yadong, Ji Shengxiang, Li Weihua, Zhang Yan, Xiong Shisheng
Center of Micro-Nano System, School of Information Science and Technology, Fudan University, Shanghai 200438, China.
State Key Laboratory of Molecular Engineering of Polymers, Key Laboratory of Computational Physical Sciences, Department of Macromolecular Science, Fudan University, Shanghai 200438, China.
iScience. 2024 Mar 4;27(4):109425. doi: 10.1016/j.isci.2024.109425. eCollection 2024 Apr 19.
Directed self-assembly (DSA) lithography has demonstrated significant potential in fabricating integrated circuits. However, DSA encounters limited processing windows due to the requirement for precise matching between the period of block copolymers (BCPs) and graphoepitaxy templates. We propose a binary BCP/homopolymer blending strategy to manipulate the self-assembly behavior and the processing window of graphoepitaxy DSA in contact hole shrinking. By carefully tailoring the blending rates of poly(methyl methacrylate) (PMMA) with different molecular weights in cylindrical polystyrene--poly(methyl methacrylate) (PS--PMMA), we manipulate the period and morphology of BCP/homopolymer self-assembly. Specifically, we employ BCP/homopolymer blending to fine-tune the critical dimension (CD) of contact holes with PS-affined topographical templates. Subsequent pattern transferring is achieved by selectively etching defect-free shrinkable cylinders as hard masks. Furthermore, self-consistent field theory (SCFT) simulation was employed to explore the self-assembly of BCP/homopolymer blending in confined cylindrical space and the results were in good consistency with the experimental results.
定向自组装（DSA）光刻技术在制造集成电路方面已展现出巨大潜力。然而，由于嵌段共聚物（BCP）周期与图形外延模板之间需要精确匹配，DSA的加工窗口有限。我们提出一种二元BCP/均聚物共混策略，以操控图形外延DSA在接触孔收缩过程中的自组装行为和加工窗口。通过精心调整圆柱形聚苯乙烯-聚甲基丙烯酸甲酯（PS-PMMA）中不同分子量的聚甲基丙烯酸甲酯（PMMA）的共混比例，我们操控了BCP/均聚物自组装的周期和形态。具体而言，我们采用BCP/均聚物共混来微调具有PS亲和性形貌模板的接触孔的关键尺寸（CD）。随后通过选择性蚀刻无缺陷的可收缩圆柱体作为硬掩膜来实现图案转移。此外，利用自洽场理论（SCFT）模拟来探究BCP/均聚物在受限圆柱形空间中的自组装，结果与实验结果高度一致。
