Method for measuring and calibrating centroid of coarse stage of photolithography tool

• Main Authors: Dong Junqing, Wu Liwei
• Format: Patent
• Language: English
• Published: 13.12.2016
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY; MATERIALS THEREFOR; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS

A method for measuring and calibrating a centroid of a coarse stage of a photolithography tool by means of measuring an offset of the centroid relative to a midpoint of the coarse stage is disclosed. The method includes: individually performing closed-loop controls on parameters of the three degrees of freedom X, Y, and Rz of the coarse stage and converting the parameters into coordinates in a coordinate system of the coarse stage (601); for each of the X and Y directions, estimating a range for the centroid (604), equally dividing the range into N parts (605), and designating each dividing point as an eccentricity (605); obtaining N Rz direction positional deviations by conducting a compensation calibration and a calibration calculation based on each corresponding eccentricity (606-611); comparing a minimum of the N positional deviations with a preset Rz-direction positional deviation threshold (613), completing the measurement if the latter is greater (614), and otherwise designating a range between the eccentricities adjacently in front of and behind the eccentricity corresponding to the minimum positional deviation as a new range for the centroid (616-617) and repeating the measurement until the minimum is smaller than the preset threshold.