OPTICAL INTEGRATOR, ILLUMINATION OPTICAL APPARATUS, EXPOSURE APPARATUS, EXPOSURE METHOD, AND DEVICE MANUFACTURING METHOD

摘要

An optical integrator has characteristics to suppress influence of relative positioning error of a pair of optical members on an illuminance distribution and on a shape of an illumination field. The optical integrator is a wavefront splitting type optical integrator (8) comprised of a first optical member (8a) and a second optical member (8b) in an order mentioned from the entrance side of light. The first optical member has a plurality of first entrance surfaces (8aa) having a refractive power in a first direction (Z-direction) and substantially no refractive power in a second direction (X-direction), and a plurality of first exit surfaces (8ab) having a refractive power in the first direction and substantially no refractive power in the second direction. The second optical member has a plurality of second entrance surfaces (8ba) having a refractive power in the second direction and substantially no refractive power in the first direction, and a plurality of second exit surfaces (8bb) having a refractive power in the second direction and substantially no refractive power in the first direction.