Molecular Dynamics Simulation of the Resist Filling Process in UV-nanoimprint Lithography
Molecular Dynamics Simulation of the Resist Filling Process in UV-nanoimprint Lithography
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DOI：
10.2494/photopolymer.34.139
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发表时间：
2021-01-01
影响因子：
0.8
通讯作者：
Taniguchi, Jun
中科院分区：
文献类型：
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作者：
Uchida, Hiroki;Imoto, Ryosuke;Taniguchi, Jun
选择和设计合适的抗蚀剂材料是成功的纳米压印光刻（NIL）技术不可或缺的。目前，NIL的图案分辨率低于10 nm。因此，原子尺度上的分析的NIL过程是需要在这一领域的进一步发展。在这项研究中，我们进行了全原子分子动力学（MD）模拟的抗蚀剂分子在紫外近红外（UV-NIL）的填充过程。为了模拟填充过程，在恒定压力（100 atm）下将具有不同沟槽宽度（1、2和3 nm）的硅模具压入由两种或四种具有不同粘度（粘度范围为4至5，566 mPa.s）的分子种类组成的不同抗蚀剂材料中。在MD模拟中，粘度低于10 mPa.s的抗蚀剂被成功地填充到3 nm宽的沟槽中。降低抗蚀剂粘度缩短了完全填充所需的时间。在由四种分子组成的抗蚀剂中，1 nm宽的沟槽优先被低粘度分子填充;因此，抗蚀剂分子在系统中不均匀地分布。这种不均匀性将导致UV固化过程之后的缺陷。分子动力学模拟还表明，当与小的抗蚀剂分子混合时，多功能抗蚀剂分子可以更容易地进入窄腔，这有利于UV-NIL制作高分辨率图案。分子动力学模拟中观察到的填充过程中的分子行为提供了有用的信息，为未来的无缺陷抗蚀剂的设计。
The selection and design of appropriate resist materials is indispensable for a successful nanoimprint lithography (NIL) technique. Currently, the pattern resolution of NIL is below 10 nm. Therefore, atomic-scale analysis of the NIL process is required for further development in this field. In this study, we performed all-atom molecular dynamics (MD) simulations of the filling process of resist molecules in ultraviolet NIL (UV-NIL). To simulate the filling process, silicon molds with different trench widths (1, 2, and 3 nm) were pressed into different resist materials composed of two or four molecular species with different viscosities (viscosity range 4 to 5,566 mPa.s) under constant pressure (100 atm). In the MD simulations, resists with viscosities lower than 10 mPa.s were successfully filled into the 3-nm wide trench. Lowering the resist viscosity shortened the time required for complete filling. In the resist consisting of four molecular species, the 1-nm-wide trench was preferentially filled by the lower-viscosity molecules; consequently, the resist molecules were non-uniformly distributed in the system. This inhomogeneity would lead to defects after the UV curing process. The MD simulations also showed that when mixed with small resist molecules, the multi-functional resist molecules can more easily enter a narrow cavity, which is advantageous for fabricating high-resolution patterns by UV-NIL. The molecular behaviors during the filling process observed in the MD simulations provide useful information for the future design of defect-free resists.