光学学报, 2006, 26 (7): 1037, 网络出版: 2006-08-28
基于套刻误差测试标记的彗差检测技术
Novel Method for Measuring Coma with Fine Overlay Test Marks
摘要
为了满足光刻机投影物镜彗差测量精度的要求,提出一种基于套刻误差测试标记的彗差检测技术,分析了彗差对套刻误差测试标记空间像的影响,详细叙述了该技术的测量原理,并利用PROLITH光刻仿真软件对不同数值孔径与部分相干因子设置下套刻误差相对于彗差的灵敏度系数进行了仿真实验。结果表明,与目前国际上通常使用的投影物镜彗差检测技术相比,该技术在传统照明条件下灵敏度系数Kz7与Kz14的变化范围分别增加了27.5%和34.3%,而在环形照明条件下则分别增加了20.4%和22.1%,因此彗差的测量精度可提高20%以上。
Abstract
In order to meet the demand of coma measurement accuracy of lithographic tool projection lens, a novel method for measuring coma based on fine overlay error metrology marks is proposed. The impact of coma on the aerial image of the fine overlay metrology marks is analyzed and the principle of the method is described in detail. The sensitivity coefficients of overlay error relative to coma are obtained by the simulation software PROLITH under different numerical aperture and partial coherent factor. The simulation results show that with the conventional illumination condition, the ranges of sensitivity coefficients Kz7 and Kz14 are increased by 27.5% and 34.3% respectively, 20.4% and 22.1% for annular illumination. Compared with the widely used projection lens coma measurement method TAMIS, the accuracy of coma measurement is increased by 20%.
马明英, 王向朝, 王帆, 施伟杰, 张冬青. 基于套刻误差测试标记的彗差检测技术[J]. 光学学报, 2006, 26(7): 1037. 马明英, 王向朝, 王帆, 施伟杰, 张冬青. Novel Method for Measuring Coma with Fine Overlay Test Marks[J]. Acta Optica Sinica, 2006, 26(7): 1037.