The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 12, 2018
Filed:
Mar. 15, 2016
Tsinghua University, Beijing, CN;
Beijing U-precision Tech Co., Ltd., Beijing, CN;
Yu Zhu, Beijing, CN;
Ming Zhang, Beijing, CN;
Anlin Chen, Beijing, CN;
Rong Cheng, Beijing, CN;
Kaiming Yang, Beijing, CN;
Feng Liu, Beijing, CN;
Yujing Song, Beijing, CN;
Fan Zhi, Beijing, CN;
Jinchun Hu, Beijing, CN;
Dengfeng Xu, Beijing, CN;
Haihua Mu, Beijing, CN;
Chuxiong Hu, Beijing, CN;
TSINGHUA UNIVERSITY, Beijing, CN;
BEIJING U-PRECISION TECH CO., LTD., Beijing, CN;
Abstract
A six-degree-of-freedom displacement measurement method for an exposure region on a wafer stage, the wafer stage comprises a coil array and a movable platform. A planar grating is fixed below a permanent magnet array of the movable platform. A reading head is fixed in a gap of the coil array. A measurement region is formed on the planar grating by an incident measurement light beam of the reading head. The reading head measures the six-degree-of-freedom displacement of the measurement region, so that the six-degree-of-freedom displacement of the exposure region is obtained through calculation. In the method, the six-degree-of-freedom displacement of the exposure region at any time is measured; the measurement complexity is reduced and the measurement precision is improved, and especially, the six-degree-of-freedom displacement of the exposure region can be precisely measured at any time even if the movable platform has high flexibility.