Photo-lithography apparatus and method of correcting off-telecentricity of the apparatus caused by shift of effective illumination source

A method of correcting illumination off-telecentricity of a photo-lithography apparatus comprising an effective illumination source, a condenser lens, a reticle, a projection lens, and an XYZ stage, these elements being aligned in a Z axis-direction in an XYZ-axes orthogonal coordinate system, wherein a reduced image of pattern on the reticle is formed on a substrate disposed on the XYZ stage, and wherein the photo-lithography apparatus further comprises means for moving said effective illumination source, a photo-detector disposed on said XYZ stage, and detecting/outputting means for detecting an off-telecentricity amount and outputting an adjustment data to said means for moving the effective illumination source, said method for correcting off-telecentricity caused by a shift of said effective illumination source in a transversal direction to an optical axis of said apparatus, comprising the steps of:

• (a) providing a reticle having a specific pattern formed on the reticle,
• (b) moving said XYZ stage within depth of focus of said apparatus such that an image of said specific pattern is detected by said photo-detector, and recording coordinates (x, y, z) when detected,
• (c) moving said XYZ stage in the Z axis-direction within depth of focus of said apparatus, and next moving said XYZ stage in the X and Y axis-directions such that said specific pattern image is again detected by said photo-detector, and recording coordinates (x', y', z') when detected, and
• (d) detecting said off-telecentricity amount by calculating (x'-x)/(z'-z) and (y'-y)/(z'-z) and outputting said adjustment data corresponding to the off-telecentricity amount to said means for moving the effective illumination source.

A method of correcting magnification off-telecentricity of a photo-lithography apparatus comprising an effective illumination source, a condenser lens, a reticle, a projection lens, and an XYZ stage, these elements being aligned in a Z axis-direction in an XYZ-axes orthogonal coordinate system, wherein a reduced image of pattern on the reticle is formed on a substrate disposed on the XYZ stage, and the photo-lithography apparatus further comprises means for moving said effective illumination source, a photo-detector disposed on said XYZ stage, and detecting/outputting means for detecting an off-telecentricity amount and outputting an adjustment data to said means for moving the effective illumination source, said method for correcting off-telecentricity caused by a shift or said effective illumination source in an optical axis-direction, comprising the steps of:

• (a) providing a reticle having four specific patterns formed at each corner of an assumed square on the reticle such that a field size can be measured by detecting the specific pattern image,
• (b) moving said XYZ stage within depth of focus of said apparatus such that an image of specific patterns is detected, and next moving said XYZ stage in the X or Y axis-direction such that the field size M is detected by detecting image of two specific patterns aligned in the X or Y axis-direction, and recording coordinate (z) and the field size (M) when said specific pattern images are detected.
• (c) moving said XYZ stage in the Z axis-direction within depth of focus of said apparatus, and next moving said XYZ stage in the X or Y axis-direction such that a field size M' is detected as in step (b), and recording coordinate (z') and a field size (M') when said specific pattern images are detected, and
• (d) detecting said off-telecentricity amount by calculating .DELTA.M/(z'-z), where .DELTA.M denotes (M'-M)/M, and outputting said adjustment data corresponding to said off-telecentricity amount to said means for moving the effective illumination source.