Citation: | ZENG Hai-feng, LI Shi-guang, LI Xian-jie. Process adaptability for digital grating-based focusing and leveling sensors[J]. Chinese Optics. doi: 10.37188/CO.2024-0021 |
In the digital grating displacement measurement technique, the CMOS pixel array of the camera is regarded as a ‘digitized’ grating. The micron-scale grating images can realize nanoscale displacement measurements by constructing the period difference between optical grating and digital grating. Combined with the detection light path of oblique incidence, it can be applied to the lithography machine’s focusing and leveling sensor to measure the wafer surface height accurately. In the actual measurement, the unexpected patterns on the wafer surface interfere with the reflection imaging of the optical grating, then affect the image processing results. In this paper, a process adaptability method for digital grating displacement measurement is proposed, which reconstructs the light intensity and recovers the light intensity curve from the CMOS image when interference patterns exist. The proposed method shows good stability when the large area pattern appears on the wafer substrate, and can adapt to multiple surface defects such as scratches, particles, stains and grooves. The experimental results show that the mean square error of the light intensity curve is significantly reduced and the method’s
[1] |
郭杰, 李世光, 赵焱, 等. 电子束硅片图形检测系统中的纳米级对焦控制技术[J]. 中国光学,2019,12(2):242-255. doi: 10.3788/co.20191202.0242
GUO J, LI SH G, ZHAO Y, et al. Nano-scale focus control technology in electron beam wafer pattern inspection system[J]. Chinese Optics, 2019, 12(2): 242-255. (in Chinese). doi: 10.3788/co.20191202.0242
|
[2] |
高旭, 李舒航, 马庆林, 等. 光栅精密位移测量技术发展综述[J]. 中国光学,2019,12(4):741-752. doi: 10.3788/co.20191204.0741
GAO X, LI SH H, MA Q L, et al. Development of grating-based precise displacement measurement technology[J]. Chinese Optics, 2019, 12(4): 741-752. (in Chinese). doi: 10.3788/co.20191204.0741
|
[3] |
李琛毅. 基于数字光栅的新型光栅尺的研究[D]. 北京: 中国科学院大学, 2021: 22-30.
LI CH Y. A novel optical encoder based on digital grating[D]. Beijing: University of Chinese Academy of Sciences, 2021: 22-30. (in Chinese) (查阅网上资料, 未找到本条文献英文翻译, 请确认并核对出版信息) .
|
[4] |
钟志坚, 李琛毅, 李世光, 等. 先进光刻中的聚焦控制预算(I)-光路部分[J]. 中国光学,2021,14(5):1104-1119. doi: 10.37188/CO.2021-0033
ZHONG ZH J, LI CH Y, LI SH G, et al. Budget analysis of focus control in advanced lithography (I) -optical path[J]. Chinese Optics, 2021, 14(5): 1104-1119. (in Chinese). doi: 10.37188/CO.2021-0033
|
[5] |
ASML Netherlands B. V. te Veldhoven. Level sensor and lithographic apparatus: NL, 2022732A[P]. 2019-10-16.
|
[6] |
Canon Kabushiki Kaisha. Lithography apparatus, lithography method, and method of manufacturing article: US, 10488764B2[P]. 2019-11-26.
|
[7] |
孙裕文, 李世光, 宗明成. 基于空间分光的纳米级调焦调平测量技术[J]. 光学学报,2016,36(5):0512002. doi: 10.3788/AOS201636.0512002
SUN Y W, LI SH G, ZONG M CH. Nanoscale focusing and leveling measurement technology based on optical spatial split[J]. Acta Optica Sinica, 2016, 36(5): 0512002. (in Chinese). doi: 10.3788/AOS201636.0512002
|
[8] |
冯金花, 胡松, 李艳丽, 等. 基于叠栅条纹相位解析的纳米检焦方法[J]. 光学学报,2015,35(2):0212005. doi: 10.3788/AOS201535.0212005
FENG J H, HU S, LI Y L, et al. Nano focusing method based on moire fringe phase analysis[J]. Acta Optica Sinica, 2015, 35(2): 0212005. (in Chinese). doi: 10.3788/AOS201535.0212005
|
[9] |
蓝科, 陈雪影, 刘逍. 沟槽晶圆调焦调平测量工艺适应性分析[J]. 中国设备工程,2021(13):125-127.
LAN K, CHEN X Y, LIU X. Adaptability analysis of measurement technology of Groove Wafer focusing and leveling[J]. China Plant Engineering, 2021(13): 125-127. (in Chinese) (查阅网上资料, 未找到本条文献英文翻译, 请确认) .
|
[10] |
郭磊. 数字光刻机中的三维位移测量系统研究[D]. 北京: 中国科学院大学, 2022: 25-31.
GUO L. Three-dimensional displacement measurement system in digital lithographic system[D]. Beijing: University of Chinese Academy of Sciences, 2022: 25-31. (in Chinese) (查阅网上资料, 未找到本条文献英文翻译, 请确认并核对出版信息) .
|
[11] |
苏绍璟. 大量程纳米级光栅位移测量理论及关键技术研究[D]. 长沙: 国防科学技术大学, 2001: 37-43.
SU SH J. Research on theory and key technologies of long-range displacement measuring with nanometer resolution by grating[D]. Changsha: National University of Defense Technology, 2001: 37-43. (in Chinese).
|
[12] |
邢丽冬, 潘双来. 信号与线性系统[M]. 3版. 北京: 清华大学出版社, 2020: 59-127.
XING L D, PAN SH L. Signal & Linear Systems[M]. 3rd ed. Beijing: Tsinghua University Press, 2020: 59-127. (in Chinese) (查阅网上资料, 未找到本条文献英文翻译, 请确认) .
|
[13] |
LEVINSON H J. Principles of Lithography[M]. 3rd ed. Bellingham, USA: SPIE, 2010: 32-46.
|
[14] |
李小平, 陈飞彪. 投影光刻机硅片调焦调平测量模型[J]. 光学学报,2007,27(11):1987-1991. doi: 10.3321/j.issn:0253-2239.2007.11.013
LI X P, CHEN F B. Measurement model of focusing and leveling measurement system for projection lithography tool[J]. Acta Optica Sinica,2007,27(11):1987-1991. (in Chinese) doi: 10.3321/j.issn:0253-2239.2007.11.013
|