Directed self-assembly (DSA) of block copolymers (BCPs) is an advanced patterning technique being investigated to obtain small and dense patterns for future technological nodes. In order to demonstrate the potential of DSA to extend optical lithography, poly(styrene-b-methyl methacrylate) (PS-b-PMMA) has been the most commonly used block copolymer in different applications, such as line/space and contact hole patterning as well as uniformity repair. However, the minimum pitch for the PS-b-PMMA system is limited to around 24 nm due to its relatively weak segregation strength. Therefore, block copolymers with stronger microphase segregation have been developed to enable sub-10 nm patterning, thus obtaining the so-called “high chi” BCPs. In this article, the silicon-containing high chi system investigated is the poly(styrene-b-1,1-dimethylsilacyclobutane) (PS-b-PDMSB) presenting a pitch of 18 nm. A one-step top coat and PS removal based on H₂/N₂ plasma that presents good selectivity and profile has been studied. The H₂/N₂ gas ratio has been investigated to understand the trade-off between obtaining high selectivity and avoiding pattern collapse. Using this approach, the pattern transfer into different underlayers is demonstrated for the high chi PS-b-PDMSB.

中文翻译：

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用于定向自组装 (DSA) 应用的含硅高 chi 嵌段共聚物的选择性等离子体蚀刻

嵌段共聚物 (BCP) 的定向自组装 (DSA) 是一种先进的图案化技术，正在研究为未来的技术节点获得小而密的图案。为了证明 DSA 扩展光刻的潜力，聚（苯乙烯-b-甲基丙烯酸甲酯）（PS- b - PMMA）已成为不同应用中最常用的嵌段共聚物，例如线/空间和接触孔图案以及均匀性修复。然而，PS- b的最小间距- PMMA 系统由于其相对较弱的偏析强度而被限制在 24 nm 左右。因此，已经开发出具有更强微相分离的嵌段共聚物，以实现亚 10 nm 的图案化，从而获得所谓的“高 chi”BCP。在本文中，研究的含硅高 chi 系统是间距为 18 nm的聚（苯乙烯-b -1,1-二甲基硅杂环丁烷）（PS- b -PDMSB）。已经研究了基于 H ₂ /N ₂等离子体的一步式面漆和 PS 去除，具有良好的选择性和轮廓。H ₂ /N ₂已对气体比率进行了研究，以了解获得高选择性和避免模式崩溃之间的权衡。使用这种方法，可以证明高 chi PS- b - PDMSB的图案转移到不同的底层。