Nikon Corporation

Muneyasu Yokota

Kei Nara

Toshio Matsuura

Seiji Miyazaki

Tsuyoshi Narabe

Atsuyuki Aoki

Tomohide Hamada

Yukio Kakizaki

Kazuaki Saiki

Masaichi Murakami

Hideji Goto

Toshinobu Morioka

Yoshio Fukami

When alignment marks, which have been previously formed on a substrate corresponding to each of two orthogonal axial directions, are detected by a microscope, a main control unit detects positions and numbers of the respective marks, and calculates stretching degrees of the substrate in the two orthogonal axial directions respectively on the basis of information on the detected positions of specified marks and information on designed positions of the specified marks. The main control unit determines a mean value of the stretching degrees by weighting each of the calculated stretching degrees in the two orthogonal axial directions in accordance with the detected numbers of the marks corresponding to each of the two orthogonal axial directions so that the determined weighted mean value of the stretching degrees is set as a magnification correction value. A magnification controller corrects, through a magnification-adjusting mechanism, a magnification of a projection optical system on the basis of the set magnification correction value. When stretching of the substrate takes place, the pattern continuity and the overlay accuracy in an intended privileged direction can be improved.

Exposure apparatus and method wherein the magnification of the

A scanning exposure apparatus is arranged to illuminate a mask, to project an image of the mask through a projection optical system onto a photosensitive substrate, and to move the mask and the photosensitive substrate relative to the projection optical system, thereby effecting exposure of an entire surface of the mask on the photosensitive substrate, and the exposure apparatus comprises a position detector which detects a relative positional relation between the mask and the photosensitive substrate; a memory which stores positional information obtained by the position detector; a position correcting device which corrects the relative positional relation between the mask and the photosensitive substrate, based on the positional information read out from the memory device; and a controller which makes the position detector detect the relative positional relation between the mask and the photosensitive substrate while the mask and the photosensitive substrate are carried past a projection region of the projection optical system to an exposure start position, and makes the position correcting device correct the relative positional relation between the mask and the photosensitive substrate, based on the positional information read out from the memory, while the mask and the photosensitive substrate are stopped at the exposure start position and/or during the exposure.

Scanning exposure apparatus and method

This invention relates to an exposure apparatus for synchronously scanning a mask and a photosensitive substrate with respect to a plurality of projection optical systems, thereby properly transferring an entire pattern area on the mask onto the photosensitive substrate. A plurality of sets of mask-side reference marks and substrate-side reference marks are arranged at positions corresponding to each other on the mask surface and the photosensitive substrate surface and at least at two positions conjugate with the plurality of projection optical systems. The displacement amount between an image of a mask-side reference mark or a substrate-side reference mark formed on the corresponding substrate-side reference mark or mask-side reference mark through the projection optical system and the position of the substrate-side reference mark and the mask-side reference mark is measured. The imaging characteristics of the plurality of projection optical systems are corrected in accordance with the displacement amount.

Exposure apparatus

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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Tokyo, Japan

Muneyasu Yokota