超大数值孔径极紫外光刻物镜的公差分析  

Tolerance Analysis of High-Numerical Aperture Extreme Ultraviolet Lithographic Objective

作　　者：孙圆圆[1] 李艳秋[1] 曹振[1] 

机构地区：[1]北京理工大学光电学院光电成像技术与系统教育部重点实验室,北京100081

出　　处：《激光与光电子学进展》2015年第12期215-221,共7页Laser & Optoelectronics Progress

基　　金：国家科技重大专项(2012ZX02702001-002)

摘　　要：超大数值孔径极紫外光刻物镜(NA>0.45)能够满足11 nm光刻技术节点的需求,而高分辨率成像对物镜系统的公差要求非常严格。针对一套数值孔径为0.50的极紫外投影物镜进行了补偿器选择和制造公差分析。通过对系统敏感元件结构参量构成的灵敏度矩阵进行奇异值分解(SVD)来选择像质补偿器。物镜系统的结构参量数目较多,而奇异值分解法要求灵敏度矩阵中结构参量数不多于像差数。为了满足奇异值分解法的要求,首先确定系统的敏感元件并选择敏感元件对应的结构参量构造灵敏度矩阵。再通过对该灵敏度矩阵进行奇异值分解确定有效的补偿器组合,从而弥补公差造成的像质恶化。采用上述方法确定了8个补偿器,并利用CODE V软件进行了公差分配。结果表明,系统波像差均方根值在97.7%的置信概率下小于0.5 nm,且最严公差控制在微米及微弧度量级。High-numerical aperture（NA〉0.45） extreme ultraviolet lithography is a promising candidate for 11 nm node lithography, and the tolerances of the objective system are rigorous due to high resolution image. The singular value decomposition（SVD） of the sensitivity matrix from sensitive mirrors is used to select efficient compensators for an extreme ultraviolet（EUV） lithographic objective with a numerical aperture of 0.50. The method requires that the amounts of configuration parameters is less than that of the aberration parameters, so the sensitive mirrors are confirmed and the sensitivity matrix is obtained by the configuration parameters of the sensitive mirrors. Then the sensitive and efficient compensators are selected to relax the other tolerances and compensate the worse of image quality by using the SVD of the sensitivity matrix. Using the above method, eight compensators are selected and other tolerances are assigned. Result shows that the RMS wavefront error of the objective system is less than 0.5 nm in the probability of 97.7% and the most rigorous tolerances are in the range of micron and microradian respectively.

关 键 词：光学设计 公差分析 奇异值分解 极紫外光刻 

分 类 号：TN305.7[电子电信—物理电子学]