Nikon Corporation

Atsuyuki Aoki

Muneyasu Yokota

Toshio Matsuura

Masaichi Murakami

Prior to exposures, the imaging characteristics of a projection optical system to be used are determined by measuring the positions of plural projection points (evaluation points) within the projection area, on a photosensitive substrate, of the projection optical system. Then the positional aberrations between the evaluation points are determined in the area of image superposition or jointing, and correcting parameters are determined so as to minimize at least the component of the aberrations in a direction, perpendicular to an extending direction patterns of a reticle. The reticle or the photosensitive substrate is rotated or shifted according to thus determined correcting parameters. This exposure method achieves the superposition or jointing of patterns, or the superposition of the jointed parts thereof, in optimum manner, according to the structure (directionality) of the patterns or the imaging characteristics of the projection optical system employed.

Exposure method

In the manufacture of a device having a relatively large area, e.g., a liquid crystal device by a lithographic technique, using at least one of a plurality of original images and defining an exposed pattern by each original image as an individual subdivision area, the position of a substrate is changed relatively upon exposure of every subdivision area to expose on the substrate a composite exposed pattern of a relatively large area composed of the plurality of abutting and combined subdivision areas. When aligning each of the original images with the substrate in accordance with predetermined target position information, the amounts of relative deviation at the abutting portions of the subdivision areas (i.e., stitching errors) are preliminarily determined and compensating values tending to reduce each of the stitching errors to less than a given tolerance value are added to the target position information, thereby effecting the alignment. Thus, the stitching accuracy is improved for the composite pattern on the whole.

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Kanagawa, Japan

Atsuyuki Aoki