Abstract: A projection exposure apparatus and method aligns a substrate with an optical axis of a lens column using one or more interferometers, mirrors, and a control device. The lens column projects a pattern from a mask onto the substrate. The optical axis of the lens column is perpendicular to the substrate. To ensure precise alignment of the lens column and the substrate, the one or more interferometers use a plurality of beams having respective paths, the lengths of which change in response to movement of the optical axis. In response to the detected changes of the interferometer beams, a control device adjusts the position of the stage so that the substrate is aligned with the optical axis of the lens column.

Abstract: A step-and-scan exposure method in which a mask has a plurality of patterns and the number of patterns to be transferred to each shot area of a photosensitive substrate varies. The scanning and stepping movements are controlled in accordance with the number of patterns transferred, and dimensions of a pattern illumination area are varied in accordance with the patterns to be transferred. Transfer of a pattern to a shot area is omitted when an image of the pattern on the shot area would extend beyond the photosensitive substrate. Elimination of exposure scanning movements for patterns that are not to be transferred permits rapid movements of the mask and the substrate to scanning start positions.

Abstract: A laser beam depicting apparatus adapted to depict a raster image by modulating a laser beam by image data and raster-scanning the laser beam by the reflecting surfaces of a rotational polygonal mirror comprises a laser source for producing a laser beam by oscillating light components of plural wavelengths at the same time, a light modulator for modulating the laser beam without causing color dispersion, a light deflector for correcting any deviation in a direction orthogonal to the deflection of the laser beam caused by the tilting error of each reflecting surface of the rotational polygonal mirror without causing color dispersion, and an f.theta. lens having its chromatic aberration corrected for condensing the laser beam deflected by the rotational polygonal mirror in order to raster-scan an object to be depicted.

Abstract: In a pattern generating system for scanning a pattern on a surface of a workpiece with a laser beam modulated by drawing data so as to form a pattern corresponding to design pattern data, a plurality of through holes are formed at predetermined positions of the workpiece. Beams transmitted through the through holes are directed to a sensor for generating a detection output representing positions of the transmitted beams. A computer generates position data of the through holes on the basis of the detection output and calculates a positional error and a deformation amount of the workpiece. A correcting device corrects the drawing on the basis of the positional error and the deformation amount.