常温微压印中抗蚀剂流动的研究及工艺优化

Flow behavior of resist in room-temperature micro-imprinting and its process optimization

为提高微压印中抗蚀剂的复型精度,利用POLYFLOW,基于流固耦合方法对常温压印过程中抗蚀剂的流动进行了有限元模拟,系统地分析了抗蚀剂的初始厚度,留膜厚度,模具的深宽比,占空比,模具下压速度等因素对抗蚀剂流动填充的影响规律。搭建了压印的可视化实验平台,通过该平台对不同工艺条件(包括抗蚀剂的初始厚度,留膜厚度以及模具的下压速度)及软模具结构(深宽比,占空比)下抗蚀剂的流动填充过程及其填充形貌进行了实时观测,并与数值计算结果进行比较。结果表明,在不影响填充效率的情况下,采用低速下压(≤1μm/s)方式,在占空比>0.375,深宽比<2时,填充度可达到90%以上。仿真和实验验证了优化的压印工艺条件和模具结构。另外,本文还引入了增加模板特征高度预留量的概念,可进一步提高复型精度。

To improve the replicating precision of resist in micro-imprinting, the POLYFLOW was used to simulate its flow behavior in room-temperature micro-imprinting based on the Fluid-Solid-Interaction（FSI） method. The effects of the initial thickness and residual thickness of the resist, the ratio of height to width and duty ratio of the mold, and the imprinting velocity of the mold on the resist flow behavior in a cavity were analyzed systematically. A platform of visual experiments was established, and the process of micro-imprinting and the profile of resist in different technological conditions were observed. Comparing the experimental results to the simulation results, it is concluded that the filling rate can come up to 90% when the imprinting velocity is slower than 1 μm/s, the duty ratio is more than 0. 375, and the ratio of height to width is less than 2. Obtained results show that the imprinting process condition and the structure of the mold have been optimized and the replicating precision can be improved by the optimized results.