[1] GUO J, LI SH G, ZHAO Y. Nano-scale focus control technology in electron beam wafer pattern inspection system[J]. Chinese Optics, 12, 242-255(2019).

[2] GAO X, LI SH H, MA Q L. Development of grating-based precise displacement measurement technology[J]. Chinese Optics, 12, 741-752(2019).

[3] [3] LI CH Y. A novel optical encoder based on digital grating[D]. Beijing: University of Chinese Academy of Sciences, 2021: 2230. (in Chinese).

[4] ZHONG ZH J, LI CH Y, LI SH G. Budget analysis of focus control in advanced lithography (I) -optical path[J]. Chinese Optics, 14, 1104-1119(2021).

[5] [5] ASML herls B. V. te Veldhoven. Level sens lithographic apparatus: NL, 2022732A[P]. 20191016.

[6] [6] Canon Kabushiki Kaisha. Lithography apparatus, lithography method, method of manufacturing article: US, 10488764B2[P]. 20191126.

[7] SUN Y W, LI SH G, ZONG M CH. Nanoscale focusing and leveling measurement technology based on optical spatial split[J]. Acta Optica Sinica, 36, 0512002(2016).

[8] FENG J H, HU S, LI Y L. Nano focusing method based on moire fringe phase analysis[J]. Acta Optica Sinica, 35, 0212005(2015).

[9] LAN K, CHEN X Y, LIU X. Adaptability analysis of measurement technology of Groove Wafer focusing and leveling[J]. China Plant Engineering, 125-127(2021).

[10] [10] GUO L. Threedimensional displacement measurement system in digital lithographic system[D]. Beijing: University of Chinese Academy of Sciences, 2022: 2531. (in Chinese).

[11] [11] SU SH J. Research on they key technologies of longrange displacement measuring with nanometer resolution by grating[D]. Changsha: National University of Defense Technology, 2001: 3743. (in Chinese).

[12] [12] XING L D, PAN SH L. Signal & Linear Systems[M]. 3rd ed. Beijing: Tsinghua University Press, 2020: 59127. (in Chinese).

[13] [13] LEVINSON H J. Principles of Lithography[M]. 3rd ed. Bellingham, USA: SPIE, 2010: 3246.

[14] LI X P, CHEN F B. Measurement model of focusing and leveling measurement system for projection lithography tool[J]. Acta Optica Sinica, 27, 1987-1991(2007).