Abstract Nanoimprint lithography (NIL) has attracted broad interests in nano/micropatterning of photonic structures, however, one of the major challenges in NIL is the defect rate due to a large demolding force which causes difficult demolding. In this work, adhesion and friction stresses were obtained from the overall demolding force through measurements of the total demolding force and the geometries of the mold patterns. The friction stress on the sidewalls is generally larger than the adhesion stress between the mold and the resist. In addition, a conformal Al2O3 layer grown via atomic layer deposition was introduced to cover the imprint mold and reduce the surface roughness on the sidewalls. Together with the coating of an anti-adhesion layer for easy mold releasing, both adhesion and friction stresses were reduced, leading to a lower total demolding force compared to the conventional mold with merely a hydrophobic surfactant layer or mold without any surface modification. The results obtained from this work will help the design and optimization of the NIL molds to mitigate the defect rate in UV-NIL.

中文翻译：

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UV纳米压印光刻中脱模力对模具表面改性的依赖性

摘要 纳米压印光刻（NIL）在光子结构的纳米/微图案化方面引起了广泛的兴趣，然而，NIL 的主要挑战之一是由于脱模力大导致脱模困难导致的缺陷率。在这项工作中，通过测量总脱模力和模具模型的几何形状，从整体脱模力中获得了附着力和摩擦应力。侧壁上的摩擦应力通常大于模具和抗蚀剂之间的粘附应力。此外，通过原子层沉积生长的共形 Al2O3 层被引入以覆盖压印模具并降低侧壁上的表面粗糙度。加上防粘层涂层，便于脱模，减少了粘附和摩擦应力，与仅具有疏水表面活性剂层或没有任何表面改性的模具相比，导致总脱模力较低。从这项工作中获得的结果将有助于 NIL 模具的设计和优化，以降低 UV-NIL 的缺陷率。