Kim Tae-Yi, Kang In-Hwa, Park Juhae, Kim Myungwoong, Oh Hye-Keun, Hur Su-Mi
Department of Polymer Engineering, Graduate School, Chonnam National University, Gwangju 61186, Republic of Korea.
Department of Applied Physics, Hanyang University, Ansan 15588, Republic of Korea.
Polymers (Basel). 2023 Apr 22;15(9):1988. doi: 10.3390/polym15091988.
Enabling extreme ultraviolet lithography (EUVL) as a viable and efficient sub-10 nm patterning tool requires addressing the critical issue of reducing line edge roughness (LER). Stochastic effects from random and local variability in photon distribution and photochemical reactions have been considered the primary cause of LER. However, polymer chain conformation has recently attracted attention as an additional factor influencing LER, necessitating detailed computational studies with explicit chain representation and photon distribution to overcome the existing approach based on continuum models and random variables. We developed a coarse-grained molecular simulation model for an EUV patterning process to investigate the effect of chain conformation variation and stochastic effects via photon shot noise and acid diffusion on the roughness of the pattern. Our molecular simulation demonstrated that final LER is most sensitive to the variation in photon distributions, while material distributions and acid diffusion rate also impact LER; thus, the intrinsic limit of LER is expected even at extremely suppressed stochastic effects. Furthermore, we proposed and tested a novel approach to improve the roughness by controlling the initial polymer chain orientation.
要使极紫外光刻（EUVL）成为一种可行且高效的亚10纳米光刻工具，需要解决降低线边缘粗糙度（LER）这一关键问题。光子分布和光化学反应中的随机和局部变化所产生的随机效应被认为是LER的主要原因。然而，聚合物链构象最近作为影响LER的一个额外因素受到了关注，因此需要进行详细的计算研究，采用明确的链表示和光子分布，以克服基于连续介质模型和随机变量的现有方法。我们开发了一个用于EUV光刻工艺的粗粒度分子模拟模型，以研究链构象变化以及通过光子散粒噪声和酸扩散产生的随机效应对图案粗糙度的影响。我们的分子模拟表明，最终的LER对光子分布的变化最为敏感，而材料分布和酸扩散速率也会影响LER；因此，即使在随机效应被极大抑制的情况下，LER的固有极限仍然存在。此外，我们提出并测试了一种通过控制初始聚合物链取向来改善粗糙度的新方法。
