| 摘要 |
A projection exposure method wherein a mask (R) is illuminated with illuminating light (ILB) for exposure, and an image of the mask pattern is projected onto a photosensitive substrate (W) through a projection optical system (PL). A phase plate is disposed on a Fourier transform plane (FTP) of the projection optical system (PL) or on a plane near the Fourier transform plane. The circular region of the phase plate of radius r2 is divided into a central circular region (FA) and a peripheral annular region (FB) when the pattern image of the mask (R) is to be transferred onto the substrate (W) by successively carrying out three divided exposure operations such that the position of the substrate (W) relative to the position of the image-forming plane of the projection optical system (PL) is changed in the optical axis direction by a distance d at a time, the distance d is set at a value which is determined according to the numerical aperture of the projection optical system (PL) and the wavelength of the illuminating light. Moreover, the amounts of exposure for two of the three divided exposure operations which are carried out at two opposite extremity positions of the exposure range in the optical axis direction are set substantially equal to each other, and the amount of exposure for one of the three divided exposure operations which is carried out at an intermediate position in the optical axis direction is set according to the distance d.
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