Patent ID: 8493549

Claim:
An illumination optical apparatus for use in an exposure apparatus for exposing a predetermined pattern onto a substrate with a projection optical system, the illumination optical apparatus illuminating the predetermined pattern using a light from a light source, the apparatus comprising: a first optical system located in an illumination path of the illumination optical apparatus, the first optical system distributing the light from the light source in a predetermined form at a position of a far field of the first optical system; a correction member having a second optical system, wherein the second optical system focuses the light, which is distributed at the position of the far field, at a first plane in the illumination path; and an optical system having an optical integrator, wherein the optical integrator forms a planar light source using the light from the second optical system, wherein the second optical system includes one or more movable lenses which are movable in the optical axis direction, and wherein the second optical system changes a position of the first plane in the optical axis direction by moving the one or more movable lenses.