Exposure apparatus and control method for correcting an exposure optical system on the basis of an estimated magnification variation
AssigneeCanon Kabushiki Kaisha
InventorMASAMI YONEKAWA
Life of this patent
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Abstract
In an exposure apparatus for projecting illumination light irradiating a reticle on a wafer via an optical system, a mark magnification variation ΔβM is calculated from the displacement amounts of a plurality of position measurement marks used for reticle alignment. From the mark magnification variation ΔβM a shot magnification ΔβS is estimated using an estimation equation having an aspect ratio A and area ratio S of the exposure region as parameters: ΔβS=c·Ap·Sq·ΔβM (where c, p, q are coefficients) The shot magnification is corrected based on the estimation result using the magnification correction function of a projection lens.
Claims28
A control method for an exposure apparatus for projecting illumination light irradiating a reticle on a member to be exposed via an optical system, comprising:
- the holding step of holding a parameter corresponding to a shape of an exposure region on the reticle;
- the measurement step of measuring a displacement of a mark formed on the reticle;
- the estimation step of estimating a magnification variation in the exposure region on the basis of the displacement of the mark measured in the measurement step and the parameter;
- and
- the correction step of correcting the optical system on the basis of the magnification variation estimated in the estimation step.
An exposure apparatus for projecting illumination light irradiating a reticle on a member to be exposed via an optical system, comprising:
- holding means for holding a parameter corresponding to a shape of an exposure region on the reticle;
- measurement means for measuring a displacement of a mark formed on the reticle;
- estimation means for estimating a magnification variation in the exposure region on the basis of the displacement of the mark measured by said measurement means and the parameter;
- and
- correction means for correcting the optical system on the basis of the magnification variation estimated by said estimation means.
Dependencies are inferred from the claim text.