Abstract. We continue our work on the physics of mask-topography-induced phase effects in imaging using extreme ultraviolet (EUV) lithography, and specifically how these effects can be mitigated by alternative mask absorbers. We present a semianalytical model to calculate the mask-topography-induced phase offset and study its trend throughout the entire material space at 13.5-nm wavelength. We demonstrate that the model is in good agreement with 3D rigorous simulations. Using the model, we explain why the previously demonstrated phase shift close to 1.2π works optimally for EUV imaging. We show a low refractive index mask absorber (n  <  0.91) is crucial for good mask 3D mitigation. We demonstrate the importance of mask bias and incident angle for imaging with an optimized attenuated phase-shift mask (PSM), which makes good source-mask optimization indispensable. We present the lithographic performance of alternative mask absorbers including a high-k mask, and a low- and high-transmission attenuated PSM for a few basic use cases, confirming the lithographic gain that can be obtained by mask-absorber optimization.

中文翻译：

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掩模吸收器优化：下一阶段

摘要。我们继续研究使用极紫外 (EUV) 光刻成像中掩模形貌引起的相位效应的物理学，特别是如何通过替代掩模吸收剂减轻这些影响。我们提出了一个半解析模型来计算掩模形貌引起的相位偏移，并研究其在 13.5 nm 波长下在整个材料空间中的趋势。我们证明该模型与 3D 严格模拟非常一致。使用该模型，我们解释了为什么先前证明的接近 1.2π 的相移最适合 EUV 成像。我们展示了低折射率掩模吸收器（n < 0.91）对于良好的掩模 3D 缓解至关重要。我们展示了掩模偏置和入射角对于使用优化的衰减相移掩模 (PSM) 进行成像的重要性，这使得良好的源掩码优化必不可少。我们针对一些基本用例展示了替代掩模吸收器的光刻性能，包括高 k 掩模，以及低和高透射衰减 PSM，证实了可通过掩模吸收器优化获得的光刻增益。