Non-orthogonal correction method for workpiece stage and correction device

Abstract

The invention discloses a non-orthogonal correction method for a workpiece stage and a correction device. The correction device comprises non-orthogonal measurement marks, which are arranged on a coarse-movement turn table on the workpiece stage, wherein the coarse-movement turn table is used for bearing a base plate, and at least three measurement marks are arranged and are not located on a samestraight line; visual units, which are used for acquiring the positions of the non-orthogonal measurement marks; an interferometer measuring unit, which is used for measuring the position of the workpiece stage; and a correction unit, which calculates the non-orthogonal amount of the workpiece stage according to the nominal positions of the non-orthogonal measurement marks in a coordinate system of the turn table, the positions of the non-orthogonal measurement marks acquired by the visual units and the position of the workpiece stage, and transmitting the non-orthogonal amount to the interferometer measuring unit for compensation and correction. The correction method and correction device provided by the invention effectively prevent TP control precision from the influence of the surfacedeformation of the workpiece stage due to heat in the process of exposure, so the usage cost of materials is reduced.

Description

technical field [0001] The invention relates to the technical field of photolithography, in particular to a non-orthogonal correction method and a correction device for a workpiece table. Background technique [0002] The projection scanning TFT (Thin Film Transistor, thin film transistor) lithography machine is used to clearly and correctly image the pattern on the mask on the substrate coated with photoresist. As the size of the substrate increases, a larger flat mirror needs to be used As the measuring mirror of the workpiece stage interferometer, the surface shape change of the square mirror has become the main factor restricting the accuracy of TP (Total Pitch). [0003] When the mirror surface changes little, usually offline periodic calibration is enough, but when the surface shape is greatly deformed by heat, the offline calibration cycle can no longer meet the needs. In addition, the change of the rotation attitude of the mirror will also affect the non-orthogonali...

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