Next-generation extreme ultraviolet (EUV) systems with numerical apertures of 0.55 have the potential to provide sub-8-nm half-pitch resolution. The increased importance of stochastic effects at smaller feature sizes places further demands on scanner and mask to provide high contrast images. We use rigorous mask diffraction and imaging simulation to understand the impact of the EUV mask absorber and to identify the most appropriate optical parameters for high NA EUV imaging. Simulations of various use cases and material options indicate two main types of solutions: high extinction materials, especially for lines spaces, and low refractive index materials that can provide phase shift mask solutions. EUV phase masks behave very different from phase shift masks for DUV. Carefully designed low refractive index materials and masks can open up a new path toward high contrast edge printing.

中文翻译：

---

高NA EUV光刻吸收材料的观点和权衡

孔径为0.55的下一代极紫外（EUV）系统具有提供低于8 nm半间距分辨率的潜力。在较小的特征尺寸下，随机效应的重要性日益提高，这对扫描仪和光罩提供高对比度图像的要求也越来越高。我们使用严格的掩模衍射和成像模拟来了解EUV掩模吸收剂的影响，并为高NA EUV成像确定最合适的光学参数。对各种用例和材料选项的仿真表明，解决方案主要有两种：高消光材料（特别是用于行空间）和低折射率材料（可提供相移掩模解决方案）。EUV相位掩模的行为与DUV的相移掩模非常不同。