Extreme ultraviolet mask roughness effects in high numerical aperture lithography.
Extreme ultraviolet mask roughness effects in high numerical aperture lithography.
复制标题
高数值孔径光刻中的极紫外掩模粗糙度效应。
DOI：
10.1364/ao.57.001724
复制
发表时间：
2018
期刊：
影响因子：
1.9
通讯作者：
T. Pistor
中科院分区：
文献类型：
--
作者：
P. Naulleau;Yow;T. Pistor
鉴于极紫外光刻的反射性质及其极短的操作波长，光学表面的粗糙度是重要的问题。特别地，掩模多层中的粗糙度导致成像过程中的图像平面散斑和最终图案化的线边缘或线宽变化。在这里，我们认为这种效应的影响，未来的高数值孔径（NA）的系统，假设需要变形放大投影光学。结果表明，显着的各向异性行为在高NA以及大幅增加相对图案线的变化在阴影方向相比，0.55 NA至0.33 NA时，尽管假设的变形放大系统。阴影方向的图案化线的可变性比无阴影线大2倍，并且可变性的大部分增加发生在低频区域。
Given the reflective nature of extreme ultraviolet lithography and its extremely short operational wavelength, roughness of the optical surfaces is of significant concern. In particular, roughness in the mask multilayer leads to image plane speckle and ultimately patterned line-edge or line-width variability in the imaging process. Here we consider the implications of this effect for future high numerical aperture (NA) systems that are assumed to require anamorphic magnification projection optics. The results show significant anisotropic behavior at high NA as well as a substantial increase in relative patterned line variability in the shadowed direction when comparing 0.55 NA to 0.33 NA, despite the assumption of an anamorphic magnification system. The shadowed-direction patterned line variability is 2× larger than for unshadowed lines, and the majority of the increase in variability occurs in the low frequency regime.