Projection exposure method and apparatus

A projection exposure apparatus comprising:

• an illumination system having a plurality of optical integrators that form different secondary light sources of which distributions are different from each other to illuminate a mask with light from a secondary light source selected based on a pattern formed on the mask and a holding member that holds the plurality of optical integrators so that one of the plurality of optical integrators that form the selected secondary light source is disposed in an optical path of the illumination system;
• and
• a projection optical system disposed between the mask and a substrate to project light from the illuminated mask onto the substrate.

A projection exposure apparatus comprising:

• an illumination system that illuminates a pattern with light from four off-axis secondary light sources formed with light from a light source and defined by a light shielding device, said illumination system including a diffraction optical element disposed between the light source and the light shielding device to generate diffracted light incident on a portion including areas in which the four off-axis secondary light sources are formed with light from the light source;
• and
• a projection optical system that projects an image of the pattern on a predetermined plane, wherein a ratio of a numerical aperture of a light beam from each of said four secondary light sources to a numerical aperture of said projection optical system is substantially 0.1 through 0.3.

A method of exposing a substrate with a pattern on a mask, the method comprising the steps of:

• arranging one of a plurality of optical integrators that form different secondary light sources of different light intensity distributions in an optical path of an illumination system, each of the secondary light sources having a different distribution, the illumination system illuminating the pattern with light from a secondary light source formed by the arranged one of the plurality of optical integrators, the arranged one of the optical integrators being arranged based on the pattern;
• and
• projecting an image of the pattern on the substrate.