Computational analysis of polymeric materials plays a key role in defining their tribological characteristics. This research investigates the deformation behavior of poly(methylmethacrylate) (PMMA) as a thermoplastic resist material for the thermal nanoimprint lithography (T-NIL) process. Molecular dynamics modeling was conducted on a PMMA substrate imprinted with a rigid spherical indenter. The effect of indenter size, force, and imprinting duration on the indentation depth, penetration depth, recovery depth, and recovery percentage of the polymer was evaluated. The results showed that the largest indenter, regardless of force, had the most significant impact on deformation behavior. The 40-Å indenter with a 1 μN of force caused the surface molecules to descend to the lowest point compared to the other indenters. An increase in the indenter size resulted in a higher penetration depth, recovery depth, and recovery percentage. Higher durations of imprint cycle (400 fs) resulted in plastic deformation of the PMMA material with minimal recovery (30 Å). The results of this research lay foundation for explaining the effect of several T-NIL process parameters on the virgin PMMA thermoplastic resist material.

中文翻译：

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纳米压印光刻中PMMA材料变形行为的分子动力学研究

聚合物材料的计算分析在定义其摩擦学特性方面起着关键作用。这项研究调查了聚甲基丙烯酸甲酯（PMMA）作为热纳米压印光刻（T-NIL）工艺的热塑性抗蚀剂材料的变形行为。分子动力学建模是在带有刚性球形压头的PMMA基板上进行的。评估压头尺寸，力和压印时间对压痕深度，穿透深度，恢复深度和聚合物的恢复百分比的影响。结果表明，无论压力大小，最大的压头对变形行为的影响最大。具有1μ的40Å压头与其他压头相比，N的力导致表面分子下降到最低点。压头尺寸的增加导致较高的穿透深度，恢复深度和恢复百分比。较长的压印周期（400 fs）导致PMMA材料发生塑性变形，而回收率极低（30Å）。这项研究的结果为解释几种T-NIL工艺参数对纯PMMA热塑性抗蚀剂材料的影响奠定了基础。