Abstract: In an alignment apparatus for aligning a mask and a photosensitive substrate (a semiconductor wafer or glass plate applied with a photoresist), and which is suitably used in a projection exposure apparatus (a stepper or aligner), a proximity exposure apparatus, or the like used in a lithography process in the manufacture of a semiconductor element or a liquid crystal display element, two first beams and two second beams differing from the first beams may be radiated on a diffraction grating-like mask mark and a diffraction grating-like substrate mark, respectively, with the two second beams passing through a transparent region adjacent to the mask mark. By detecting diffracted light components of the two first beams and detecting diffracted light components of the two second beams, a relative position shift between the mask and the substrate can be determined.

Abstract: A scanning exposure apparatus has a mask (reticle) and a photosensitive substrate (a wafer) in an imaging relationship across a projection optical system. A mask stage and a wafer stage are moved simultaneously in first (X) direction with a speed ratio corresponding to the magnification of projection, so that a shot area of the photosensitive substrate is scan-exposed to an original pattern of the mask.The mask is provided, over the scanning range of the original pattern, with mask gratings, each composed of plural grating elements arranged at a predetermined pitch along the first (X) direction. The photosensitive substrate is provided with substrate gratings corresponding to said mask gratings. The positional aberration between said mask gratings and the substrate gratings is detected, through the projection optical system, by positional aberration detecting means.

Abstract: A projection exposure apparatus comprises a projection optical system for forming an image of a predetermined pattern on a mask onto a photosensitive substrate under exposure light having a first wavelength, an illumination system for illuminating a mask on the photosensitive substrate with light having a second wavelength different from the first wavelength through the projection optical system so as to attain alignment, and a detection system for detecting light reflected by the mark. The illumination system comprises a light source for emitting the light having the second wavelength, a first field stop for defining an illumination field on the photosensitive substrate and a second field stop for defining an illumination field on the photosensitive substrate.