At-wavelength extreme ultraviolet lithography mask inspection using a Mirau interferometric microscope
At-wavelength extreme ultraviolet lithography mask inspection using a Mirau interferometric microscope
复制标题
使用 Mirau 干涉显微镜进行波长极紫外光刻掩模检查
DOI：
10.1116/1.1319702
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发表时间：
2000
影响因子：
1.4
通讯作者：
M. Fukuda
中科院分区：
文献类型：
--
作者：
T. Haga;H. Takenaka;M. Fukuda
我们开发了一种用于极紫外光刻 (EUVL) 掩模的新型波长检测系统，该系统采用 EUV 干涉显微镜。该系统的主要优点是能够直接观察掩模并检测缺陷本身，从而即使在带有吸收器的成品掩模中也可以检测到相位缺陷。此外，该系统还提供 EUV 显微镜的高空间分辨率、干涉测量的高相位分辨率以及高吞吐量。我们使用几种具有编程缺陷的 EUVL 掩模研究了缺陷检测能力，发现可以检测步长低至 5 nm 的编程相位缺陷。这些结果证明了 Mirau 干涉显微镜在波长 EUVL 掩模检查方面的能力。考虑到史瓦西光学的衍射极限分辨率（∼50 nm），该系统应该适用于百纳米技术节点。
We have developed a novel at-wavelength inspection system for extreme ultraviolet lithography (EUVL) masks that employs an EUV interferometric microscope. The main advantage of this system is the ability to observe a mask directly and detect defects as they are, thus allowing phase defects to be detected even in a finished mask with the absorber. Moreover, this system provides the high spatial resolution of an EUV microscope, the high phase resolution of interferometric measurements, and a high throughput. We investigated the defect detection capability using several types of EUVL masks with programmed defects, and found that programmed phase defects with steps as low as 5 nm can be detected. These results demonstrate the capabilities of a Mirau interferometric microscope for at-wavelength EUVL mask inspection. Considering the diffraction-limited resolution of Schwarzschild optics (∼50 nm), this system should be applicable to the subhundred nanometer technology node.