Effect of surface tension and coefficient of thermal expansion in 30 nm scale nanoimprinting with two flexible polymer molds
Effect of surface tension and coefficient of thermal expansion in 30 nm scale nanoimprinting with two flexible polymer molds
复制标题
使用两个柔性聚合物模具进行 30 nm 级纳米压印时表面张力和热膨胀系数的影响
DOI：
10.1088/0957-4484/23/23/235303
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发表时间：
2012
期刊：
影响因子：
3.5
通讯作者：
K. Suh
中科院分区：
文献类型：
--
作者：
Jae kwan Kim;H. Cho;Ho;Kipil Lim;Ki;D. Choi;Jun‐ho Jeong;K. Suh
我们报告纳米压印聚合物薄膜在30 nm尺度分辨率使用两种类型的紫外线（UV）固化，灵活的聚合物模具：全氟聚醚（PFPE）和聚氨酯丙烯酸酯（普阿）。结果发现，在30纳米尺度的纳米图案化的质量在很大程度上是由表面张力和聚合物模具的热膨胀系数的组合效应决定的。特别是，表面张力的极性分量可能在模具的清洁脱模中发挥关键作用，正如在图案化相对亲水性的PMMA薄膜时，极性较小的PFPE模具的分层或破碎结构大大减少所证明的那样。相比之下，对于两种聚合物模具，用相对疏水的PS膜没有明显观察到这样的问题。此外，脱模特性还受热膨胀系数的影响，使得当在室温下图案化UV可固化聚合物膜时没有观察到分层或均匀性问题。这些结果表明，需要选择合适的聚合物模具材料用于在不同的表面性质和加工条件下图案化聚合物膜，从而提供对如何在30 nm尺度纳米图案化下获得清洁脱模特性的见解。
We report on nanoimprinting of polymer thin films at 30 nm scale resolution using two types of ultraviolet (UV)-curable, flexible polymer molds: perfluoropolyether (PFPE) and polyurethane acrylate (PUA). It was found that the quality of nanopatterning at the 30 nm scale is largely determined by the combined effects of surface tension and the coefficient of thermal expansion of the polymer mold. In particular, the polar component of surface tension may play a critical role in clean release of the mold, as evidenced by much reduced delamination or broken structures for the less polarized PFPE mold when patterning a relatively hydrophilic PMMA film. In contrast, such problems were not notably observed with a relatively hydrophobic PS film for both polymer molds. In addition, the demolding characteristic was also influenced by the coefficient of thermal expansion so that no delamination or uniformity problems were observed when patterning a UV-curable polymer film at room temperature. These results suggest that a proper polymeric mold material needs to be chosen for patterning polymer films under different surface properties and processing conditions, providing insights into how a clean demolding characteristic can be obtained at 30 nm scale nanopatterning.