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变焦系统的设计要求中心波长365 nm,入瞳直径Φ33 mm,视场角±1.35°,像面直径Φ30~120 mm,后工作距离≥200 mm,像方远心度≤10 mrad,畸变≤±2%。根据变焦系统的设计要求,采用CODE V软件设计的变焦系统光路如图1所示,设计结果和满意度分析如表1所示。
表 1 设计结果与设计要求对照表
Table 1. Comparison table of design results and design requirements
Parameters Design requirements Design results Wavelength/nm 365 365 Entrance pupil diameter/mm 33 33 Field/(°) ±1.35 ±1.35 Image surface diameter/mm Φ30-120 Φ30-120 After working distance/mm ≥200 300 Image surface
telecentric degrees/mrad≤10 ≤5.1 Distortion ≤±2% ≤±0.6%
Design and tolerance analysis of the zoom system in 365 nmUV lithography illumination system
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摘要: 照明系统是投影光刻曝光光学系统的重要组成部分,它实现的功能是为掩模面提供高均匀性照明、控制曝光剂量以及不同照明模式。变焦系统作为光刻照明系统的重要组成部分,对提高整个光刻机的性能起着至关重要的作用。文中针对紫外光刻照明系统的特点,采用CODE V软件完成了波长365 nm,入瞳直径Φ33 mm,像方远心度≤10 mrad,畸变≤±2%近紫外光刻照明系统中变焦系统的设计,分析了变焦系统的误差源对系统光瞳性能的影响,结合变焦系统的设计方案和实际加工能力,给出单面厚度公差需小于20 μm,动件移动精度小于0.5 nm,各透镜偏心公差小于0.02 mm,各透镜倾斜公差控制在1′之内。制定公差合理、可行,满足了紫外光刻照明系统高均匀性、高能量利用率的要求。Abstract: The illumination system is an important part of the projection lithography exposure optical system. Its function is to provide high uniformity illumination and control the exposure dose and different illumination modes for the mask surface. As an important part of the lithography lighting system, the zoom system plays a vital role in improving the performance of the entire lithography machine. According to the characteristics of the ultraviolet lithography illumination system, this paper uses CODE V software to complete the design of the zoom system in the near ultraviolet lithography illumination system with a wavelength of 365 nm, an entrance pupil diameter of Φ33 mm, an image telecentricity ≤10 mrad, and a distortion ≤±2%. The effect of the error source of the zoom system on the pupil performance of the system is analyzed, combined with the design scheme of the zoom system and the actual processing capability, gives a single-sided thickness tolerance of less than 20 μm, a moving part movement accuracy of less than 0.5 nm, and an eccentric tolerance of less than 0.02 mm for each lens. The tilt tolerance of each lens is controlled within 1′. The tolerances are reasonable and feasible, and meet the requirements of high uniformity and high energy utilization of the UV lithography illumination system.
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表 1 设计结果与设计要求对照表
Table 1. Comparison table of design results and design requirements
Parameters Design requirements Design results Wavelength/nm 365 365 Entrance pupil diameter/mm 33 33 Field/(°) ±1.35 ±1.35 Image surface diameter/mm Φ30-120 Φ30-120 After working distance/mm ≥200 300 Image surface
telecentric degrees/mrad≤10 ≤5.1 Distortion ≤±2% ≤±0.6% -
[1] 赵阳. 深紫外光刻复杂照明光学系统设计[D]. 中国科学院长春光学精密机械与物理研究所, 2010. Zhao Yang. Design of complex illumination optical system for deep ultraviolet lithogrpahy[D]. Changchun: Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 2010. (in Chinese) [2] Dorodnyy A, Shklover V, Braginsky L, et al. High-efficiency spectrum splitting for solar photovoltaic [J]. Solar Energy Materials & Solar Cells, 2015, 136(10): 120-126. [3] Zhang L, Liu D, Shi T, et al. Practical and accurate method for aspheric misalignment aberrations calibration in non-null interferometer testing [J]. Applied Optics, 2013, 52(35): 8501-8511. doi: 10.1364/AO.52.008501 [4] 张巍, 巩岩. 投影光刻离轴照明用衍射光学元件设计[J]. 光学精密工程, 2008, 16(11): 2081-2086. doi: 10.3321/j.issn:1004-924X.2008.11.007 Zhang Wei, Gong Yan. Design of diffractive optical elements for off-axis illumination in projection lithography [J]. Opt Precision Eng, 2008, 16(11): 2081-2086. (in Chinese) doi: 10.3321/j.issn:1004-924X.2008.11.007 [5] 宋强, 朱菁, 王健. 基于混合梯度下降的高性能光刻机离轴照明衍射光学元件设计[J]. 光学学报, 2015, 35(1): 0122005-1-0122005-9. Song Qiang, Zhu Jing, Wang Jian. A mixed gradient algorithm for high performance DOE design in off axis lithography illumination system [J]. Acta Optica Sinica, 2015, 35(1): 0122005. (in Chinese) [6] 张巍, 梁传样, 李金, 等. 用于激光数字投影显示系统的匀光整形元件设计[J]. 光学学报, 2015, 35(80): 0805001-1-0805001-8. Zhang Wei, Liang Chuanyang, Li Jin, et al. Design of opticelements for beam shaping and unigorm illumination in laser digital projection display system [J]. Acta Optica Sinica, 2015, 35(8): 0805001. (in Chinese) [7] 李美萱, 李宏, 张斯淇, 郭明, 付秀华. 基于浸没式光刻光束稳定系统的反射镜[J]. 光子学报, 2019, 48(02): 46-55. Li Meixuan, Li Hong, Zhang Siqi, et al. Research on mirrors of beam stabilization system for immersion lithography [J]. Acta Photonica Sinica, 2019, 48(2): 0222003. (in Chinese) [8] 李美萱, 王丽, 董连和. 光刻曝光系统中新型光可变衰减器的研制[J]. 中国激光, 2018, 45(01): 135-140. Li Meixuan, Wang Li, Dong Lianhe, et al. Development of a novel optical variable attenuator in lithography exposure system [J]. Chinese Journal of Lasers, 2018, 45(1): 0103002. (in Chinese) [9] 李美萱, 王丽, 董连和. 浸没式光刻照明系统中非球面变焦系统[J]. 光子学报, 2018, 47(1): 0120002. Li Meixuan, Wang Li, Dong Lianhe. Design of aspherical zoom optical system in immersion lithography lighting system [J]. Acta Photonica Sinica, 2018, 47(1): 0120002. (in Chinese) [10] 李美萱, 李宏, 张斯淇, 张文颖, 郭明. 基于离散抽样加密算法的衍射光学元件设计[J]. 红外与激光工程, 2019, 48(9): 0916004. Li Meixuan, Li Hong, Zhang Siqi, et al. Design of diffractive optical element based on discrete sampling encryption algorithm [J]. Infrared and Laser Engineering, 2019, 48(9): 0916004. (in Chinese) [11] Li Meixuan, Kan Xiaoting, Wang Meijiao. Design and analysis on a novel uniform compensator in lithography lighting system [J]. Laser & Infrared, 2019, 49(1): 105-109. (in Chinese) [12] Li Meixuan, Wang Meijiao, Wang Li, et al. Design and tolerance analysis of compound eye lens in lithography lighting system [J]. Laser & Infrared, 2017, 47(7): 842-847. (in Chinese)