先进光刻中的聚焦控制预算(I)-光路部分

钟志坚; 李琛毅; 李世光; 郭磊; 韦亚一

doi:10.37188/CO.2021-0033

先进光刻中的聚焦控制预算(I)-光路部分

doi: 10.37188/CO.2021-0033

钟志坚^{1, 2,},
李琛毅^{1, 2},
李世光^{1, 2, 3, ,},
郭磊^{1, 2, 3},
韦亚一^{1, 2}

1.
中国科学院微电子研究所，北京 100029
2.
中国科学院大学，北京 100049
3.
江苏影速集成电路装备股份有限公司，无锡 214142

基金项目: 国家自然科学基金资助项目(No. 61804174；No. 61604172)

详细信息

作者简介:
钟志坚（1996—），男，江西赣州人，硕士研究生，2018年于武汉理工大学获得学士学位，主要从事光刻对焦控制与检测方面的研究。E-mail：zhongzhijian18@mails.ucas.ac.cn

李世光（1973—），女，辽宁沈阳人，研究员，硕士生导师。1993年和1996年于哈尔滨工业大学分别获得学士、硕士学位，2005年于清华大学获得博士学位，2005-2011年分别于新加坡南洋理工大学和美国北卡罗来纳大学做博士后，主要从事光刻技术和光学测量的研究。E-mail：lishiguang@tsinghua.org.cn

中图分类号: TP394.1；TH691.9
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出版历程
- 收稿日期: 2021-02-01
- 修回日期: 2021-03-08
- 网络出版日期: 2021-04-30
- 刊出日期: 2021-09-18

Budget analysis of focus control in advanced lithography (I) -optical path

ZHONG Zhi-jian^{1, 2
,},
LI Chen-yi^{1, 2},
LI Shi-guang^{1, 2, 3
, ,},
GUO Lei^{1, 2, 3},
WEI Ya-yi^{1, 2}

1.
Institute of Microelectronics of the Chinese Academy of Sciences, Beijing 100029, China
2.
University of Chinese Academy of Sciences, Beijing 100049, China
3.
Jiangsu Yingsu Integrated Circuit Equipment Co., Ltd, Wuxi 214142, China

Funds: Supported by National Natural Science Foundation of China (No. 61804174; No. 61604172)

More Information

Corresponding author: lishiguang@tsinghua.org.cn

摘要

摘要: 随着大规模集成电路芯片制造的技术节点不断缩小，光刻机的聚焦控制变得尤为困难。为了保证硅片曝光的质量，需要快速、准确地将硅片在几十纳米的聚焦深度范围（DOF）内进行快速调整。因此，需要仔细分析光刻过程中导致焦点偏移或工艺窗口变化的各种因素，制定合理的聚焦控制预算，将各种误差因素控制在一定范围内。本文聚焦极紫外（EUV）光刻，综述包含EUV在内的先进光刻机中光路部分对聚焦控制有影响的各种因素，总结它们产生的原理及仿真、实验结果，为开展先进光刻聚焦控制预算研究提供参考。
- 聚焦控制 /
- 光刻 /
- 预算 /
- 最佳焦点 /
- 聚焦深度 /
- 工艺窗口
Abstract: As the technology node of large-scale integrated circuits continues to shrink, the focus control of the lithographic tools becomes particularly difficult. In order to ensure the exposure quality of wafers, it is necessary to quickly and accurately adjust the wafer in the Depth of Focus (DOF) to a degree as small as few dozen of nanometers. For this reason, people need to carefully analyze the various factors that cause defocusing or process window changes in the lithographic process, make a reasonable focus control budget, and control the various error factors within a certain range. This paper focuses on Extreme Ultraviolet (EUV) lithography, reviews the factors that affect focus control in the optical path of an advanced EUV lithographic tool and summarizes their principles, simulation and experimental results. It can provide a reference when conducting advanced lithography focus control budget research.
- focus control /
- lithography /
- budget /
- best focus /
- depth of focus /
- process window

HTML全文

图 1 EUV光刻机中的光路示意图^[11]

Figure 1. Schematic diagram of optical system of EUV lithography machine^[11]

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图 2 NXE:3100在不同光照条件下（常规，环形，双极）获得的光刻胶图案的电子显微照片^[14]

Figure 2. Electron micrographs of photoresist patterns obtained by NXE:3100 under conventional, circular, dipole illuminations^[14]

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图 3 EUV入射光锥与出射光锥的重叠与不重叠状态

Figure 3. The overlapping and non-overlapping states of the exiting light cone and the incident light cone in EUV

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图 4 EUV掩模结构

Figure 4. Structure of EUV mask

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图 5 在双极TE照明下的一维图形(光栅)成像

Figure 5. One-dimensional graphic (grating) imaging under dipole TE illumination

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图 6 Kirchhoff和三维模型下的掩模最佳焦点的偏移情况^[26]

Figure 6. Best focus shift of the mask with Kirchhoff and the 3D model^[26]

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图 7 焦点偏移与pitch间的关系^[27]

Figure 7. Relationship between focus shift and pitch^[27]

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图 8 0级和1级的衍射相位随图形周期的变化情况^[28]

Figure 8. Results of diffraction phase of the 0th and 1st order varying with pitch^[28]

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图 9 64 nm、96 nm周期线条下的最佳焦点（点）和聚焦深度（柱）^[34]

Figure 9. Best focus(point) and DOF(bar) of different pitches (64 nm, 96 nm)^[34]

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图 10 掩模弯曲对聚焦偏移的影响^[37]

Figure 10. Effect of mask bending on focus shift^[37]

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图 11 EUV光刻机中的掩模聚焦偏移

Figure 11. Mask defocus of EUV lithography machine

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图 12 泽尼克多项式^[41]

Figure 12. Zernike polynomials^[41]

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图 13 像散与场曲对UDOF的影响^[42]

Figure 13. Effects of astigmatism and field curvature on UDOF^[42]

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图 14 曝光导致的透镜热效应

Figure 14. Lens heating caused by exposure

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图 15 (a)波前校正前的(b)波前校正后公共聚焦深度^[44]

Figure 15. Common UDOFs (a) without and (b) with appling wavefront^[44]

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图 16 杂散光对聚焦深度的影响^[50]

Figure 16. Effect of flare on depth of focus^[50]

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图 17 光刻胶三维效应导致最佳焦点偏移

Figure 17. Best focus shift caused by resist 3D effect

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图 18 亮掩模和暗掩模上不同图形的最佳焦点^[56]

Figure 18. Best focus through pitch on bright and dark mask^[56]

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