Abstract: In the first step of an exposure method of the present invention, an alignment optical system is arranged to oppose one of a first mask mark on a photomask and a first substrate mark on a photosensitive substrate, thereby detecting a first deviation amount between the position of the first mask mark and that of the first substrate mark. In the second step, the alignment optical system is arranged to oppose one of a second mask mark on the photomask and a second substrate mark on the photosensitive substrate, thereby detecting a second deviation mark between the position of the second mask mark and that of the second substrate mark. In the third step, correction values for minimizing the first and second deviation amounts are calculated. In the fourth step, the relative positional relationship between the image of an original pattern on the photomask and a shot area on the photosensitive substrate is adjusted on the basis of a correction value.

Abstract: 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.

Abstract: The present invention is directed to scanning exposure apparatus and exposure method to achieve simultaneous projection of images of plural regions on a mask onto a photosensitive substrate with correcting an orthogonality error of a pattern on the mask or photosensitive substrate. If the pattern on the mask or photosensitive substrate has an orthogonality error causing a deviation of a certain angle in a first direction perpendicular to a scanning direction as it goes in the scanning direction, the mask and the photosensitive substrate are rotated relative to each other in the plane thereof to align one coordinate axis in a coordinate system of each pattern with the first direction.

Abstract: A distillation process is used to separate methanol from a mixture of methanol with methyl acrylate or methyl methacrylate, as well as from a mixture of methanol and water with methyl acrylate or methyl methacrylate with the use of an azeotropic solvent, which forms an azeotropic mixture with methanol. In distilling such a mixture by the use of a distillation column:(1) part of the condensate of vapors distilled over from the top of the distillation column top is returned to the top of the column;(2) the remaining condensate is separated into two layers;(3) the upper layer essentially composed of an azeotropic solvent from the two separated layers is fed to an intermediate portion of the distillation column;(4) the lower layer essentially composed of methanol from the above two separated layers is withdrawn from the distillation system; and(5) methyl acrylate or methyl methacrylate, or else, methyl acrylate or methyl methacrylate and water, are recovered from the bottom of the column.