摘要
提出一种基于空间像峰值光强差的光刻投影物镜奇像差测量技术。根据Hopkins部分相干成像理论,推导双缝图形空间像光强分布以及峰值光强差的解析表达式。该测量技术以双缝图形为测量标记,以空间像峰值光强差为测量对象。与基于成像位置偏移量的奇像差测量技术相比,基于峰值光强差的奇像差测量技术降低了对空间像定位精度的要求,并且高精度的光强度测量有效地提高了该技术的奇像差测量精度。利用光刻仿真软件PROLITH分析了传统照明与二极照明方式下该技术的奇像差测量精度,仿真结果表明采用二极照明具有更高的测量精度。以彗差Z7为例,在传统照明和二极照明方式下,Z7的测量精度分别达到了0.29nm与0.19nm。
An odd aberration measurement technique based on peak intensity difference of aerial image is proposed for lithographic projection lens. By using the Hopkins theory of partially coherent imaging, the analytical expressions of the aerial image and the peak intensity difference are derived for the double-slit pattern. This technique adopts a double-slit pattern as the measurement mark and the peak intensity difference of aerial image as the measurement parameter. Compared with the odd aberration measurement techniques based on image placement error （IPE）, the technique based on the peak intensity difference can reduce the requirement for positioning accuracy of the aerial image, and accurate intensity measurement can improve the odd aberration measurement accuracy effectively. The odd aberration measurement accuracies under conventional illumination and dipole illumination are analyzed with PROLITH software. The simulation results show that the measurement accuracy can be further improved under dipole illumination. Taking coma Z7 as an example, the measurement accuracies are up to 0.29 nm and 0. 19 nm under conventional illumination and dipole illumination, respectively.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2013年第5期123-129,共7页
Acta Optica Sinica
基金
国家自然科学基金(60938003
61205102
61275207)资助课题
关键词
光学制造
光刻投影物镜
波像差测量
泽尼克系数
峰值光强差
optical fabrication
lithographic projection lens
wavefront aberration measurement
Zernikecoefficient
peak intensity difference
