| 摘要 |
A method for determining and calibrating substrate plane tilt and image plane tilt in a photolithography system, which includes subjecting a test substrate to multiple exposure series to form image from which image plane tilt and substrate plane tilt about the first axis can be separately determined. For a first exposure series, two test areas aligned along a second axis are subject to the same exposures at the same position along a third axis orthogonal to the horizontal reference plane. The image from this exposure series would indicate the presence of substrate plane tilt if the relative locations of the best focus images in the test areas were substantially different. For a second exposure series, the substrate plane is stepped along the third axis direction and at least one of the test areas is subjected to the same exposure at different positions in the third axis direction. The image from this second exposure series provides information on the change in position of best focus across the substrate plane, corresponding to changes in substrate position along the third axis direction. Such information is used for determining the image plane tilt and substrate plane tilt with respect to the substrate plane. The image plane tilt and substrate plane tilt information may be used to calibrate the photolithography system for processing production substrates.
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