title: Multi-Repeated Projection Lithography for High-Precision Linear Scale Based on Average Homogenization Effect.
abstract: A multi-repeated photolithography method for manufacturing an incremental linear scale using projection lithography is presented. The method is based on the average homogenization effect that periodically superposes the light intensity of different locations of pitches in the mask to make a consistent energy distribution at a specific wavelength, from which the accuracy of a linear scale can be improved precisely using the average pitch with different step distances. The method's theoretical error is within 0.01 µm for a periodic mask with a 2-µm sine-wave error. The intensity error models in the focal plane include the rectangular grating error on the mask, static positioning error, and lithography lens focal plane alignment error, which affect pitch uniformity less than in the common linear scale projection lithography splicing process. It was analyzed and confirmed that increasing the repeat exposure number of a single stripe could improve accuracy, as could adjusting the exposure spacing to achieve a set proportion of black and white stripes. According to the experimental results, the effectiveness of the multi-repeated photolithography method is confirmed to easily realize a pitch accuracy of 43 nm in any 10 locations of 1 m, and the whole length accuracy of the linear scale is less than 1 µm/m.
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. rendongxu313@126.com.
authors.forename: Dongxu
authors.initials: D
authors.lastname: Ren
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. zhaohuiying@mail.xjtu.edu.cn.
authors.forename: Huiying
authors.initials: H
authors.lastname: Zhao
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. zcp1988123@126.com.
authors.forename: Chupeng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. 18608160633@wo.cn.
authors.forename: Daocheng
authors.initials: D
authors.lastname: Yuan
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. 13810533839@163.com.
authors.forename: Jianpu
authors.initials: J
authors.lastname: Xi
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. xueliang.zhu@foxmail.com.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Zhu
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. banxinxing405@163.com.
authors.forename: Xinxing
authors.initials: X
authors.lastname: Ban
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. dlc521@163.com.
authors.forename: Longchao
authors.initials: L
authors.lastname: Dong
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. guyawen@stu.xjtu.edu.cn.
authors.forename: Yawen
authors.initials: Y
authors.lastname: Gu
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China. jiangchunye1992@stu.xjtu.edu.cn.
authors.forename: Chunye
authors.initials: C
authors.lastname: Jiang
keywords: average homogenization effect; linear displacement sensor; linear scale; multi-repeated method; projection lithography