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:
Feb. 09, 2016
Filed:
Mar. 21, 2012
LI Fang, Shanghai, CN;
Gang Sun, Shanghai, CN;
Jinhua Min, Shanghai, CN;
Jun Zhang, Shanghai, CN;
SHANGHAI MICRO ELECTRONICS EQUIPMENT CO., LTD., Shanghai, CN;
Abstract
A method for measuring distortion of a projection objective, which includes: obtaining a plurality of first positional deviations between two groups of patterns formed respectively after two exposures performed in a same exposure field during a stepping and exposing process of the reticle stage (S); obtaining a plurality of second positional deviations between two groups of patterns formed respectively after another two exposures performed in a same exposure field during a stepping and exposing process of the workpiece stage (S); subtracting motional errors of the reticle stage and/or workpiece stage from each of the plurality of first and second positional deviations to obtain corresponding first and second corrected deviations (S, S); calculating differences each between a pair of corrected deviations (S); and calculating the distortion of the projection objective by a fitting process (S).