METHOD FOR CALIBRATING LITHOGRAPHY APPARATUS, ALIGNMENT METHOD, COMPUTER PROGRAM, LITHOGRAPHY APPARATUS AND METHOD FOR FABRICATING DEVICE TO CALCULATE DISTORTION OF SUBSTRATE IMAGE

摘要

PURPOSE: A method for calibrating a lithography apparatus is provided to compensate for the distortion of a substrate image by calculating a displacement vector between the position of a measured mark with respect to each point and the real position of a substrate. CONSTITUTION: A displacement vector between the position of a mark on the backside surface of a reference substrate measured through a front-to-backside alignment optics and the real position of the mark is calculated. The reference substrate is transferred by a small distance with respect to the front-to-backside alignment optics. A degree that the image of one point on the backside surface of the reference substrate is transferred is compared with a degree that one point on the front surface of the reference substrate is transferred, so that the first correction vector. The process that the reference substrate is transferred is repeated with respect to different points on the reference substrate so as to generate the second correction vector. The displacement vector and the optical correction vectors are calibration information.