The illumination optical system for illuminating an illumination target surface with light from a light source is provided with a polarization converting member which converts a polarization state of incident light to form a pupil intensity distribution in a predetermined polarization state on an illumination pupil of the illumination optical system; and a phase modulating member which is arranged in the optical path on the illumination target surface side with respect to the polarization converting member and which transmits light from the pupil intensity distribution so as to convert linearly polarized light thereof polarized in a first direction, into required elliptically polarized light and maintain a polarization state of linearly polarized light polarized in a second direction (X-direction or Y-direction) obliquely intersecting with the first direction, in order to reduce influence of retardation caused by a subsequent optical system between the polarization converting member and the illumination target surface.

A method to improve a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic apparatus, the method including: computing a multi-variable cost function, the multi-variable cost function being a function a plurality of design variables that represent characteristics of the lithographic process; and reconfiguring one or more of the characteristics of the lithographic process by adjusting one or more of the design variables until a certain termination condition is satisfied; wherein a bandwidth of a radiation source of the lithographic apparatus is allowed to change during the reconfiguration.

An exposure method and apparatus for illuminating a pattern with an illumination system to expose a substrate through a projection system. The pattern is illuminated with illumination light with a light amount distribution in which an amount of light is larger in a pair of first areas and a pair of second areas than in an area other than the first and second areas on a pupil plane of the illumination system. The pair of the first areas being arranged outside an optical axis, the pair of the second areas being arranged on ten same straight line as the pair of the first areas are arranged on, and the pair of the second areas being arranged outside the pair of the first areas.

An exposure apparatus includes a polarizing member polarizing illumination light, and a filter having at least one opening. The polarizing member includes a first polarizing unit and a second polarizing unit arranged so as to surround the first polarizing unit. The second polarizing unit is configured so as to polarize the illumination light entering the second polarizing unit in the circumferential direction along the outer circumference of the first polarizing unit. At least a portion of the first polarizing unit is configured to polarize the illumination light in the direction orthogonal to the polarization direction in a part of the second polarizing unit located on the side opposite to the central part of the first polarizing unit. The openings are arranged in the filter so that the illumination light at the post stage of the filter and the polarizing member includes the illumination light polarized by the first and second polarizing units.

There is disclosed a polarization-modulating element for modulating a polarization state of incident light into a predetermined polarization state, the polarization-modulating element being made of an optical material with optical activity and having a circumferentially varying thickness profile.

The illumination optical system for illuminating an illumination target surface with light from a light source is provided with a polarization converting member which converts a polarization state of incident light to form a pupil intensity distribution in a predetermined polarization state on an illumination pupil of the illumination optical system; and a phase modulating member which is arranged in the optical path on the illumination target surface side with respect to the polarization converting member and which transmits light from the pupil intensity distribution so as to convert linearly polarized light thereof polarized in a first direction, into required elliptically polarized light and maintain a polarization state of linearly polarized light polarized in a second direction (X-direction or Y-direction) obliquely intersecting with the first direction, in order to reduce influence of retardation caused by a subsequent optical system between the polarization converting member and the illumination target surface.

There is disclosed a polarization-modulating element for modulating a polarization state of incident light into a predetermined polarization state, the polarization-modulating element being made of an optical material with optical activity and having a circumferentially varying thickness profile.

A scatterometry measurement system includes an objective lens with a central obscuration and an illumination source configured to illuminate a scatterometry target through the objective lens with a first illumination beam at a first illumination angle and a second illumination beam at a second illumination angle in which the scatterometry target includes periodic structures located in at least two layers. The objective lens collects at least one diffracted order from the first illumination beam and at least one diffracted order from the second illumination beam such that the at least one diffracted order from the first illumination beam and the at least one diffracted order from the second illumination beam have a non-overlapping distribution in a portion of an imaging pupil plane not blocked by the central obscuration.

An imaging optical unit for EUV projection lithography serves to image an object field into an image field. Mirrors guide imaging light from the object field to the image field. An aperture stop is tilted by at least 1 in relation to a normal plane which is perpendicular to an optical axis. The aperture stop has a circular stop contour. In mutually perpendicular planes, a deviation of a numerical aperture NA.sub.x measured in one plane from a numerical aperture NA.sub.y measured in the other plane is less than 0.003, averaged over the field points of the image field. What emerges is an imaging optical unit, in which homogenization of an image-side numerical aperture is ensured so that an unchanging high structure resolution in the image plane is made possible, independently of an orientation of a plane of incidence of the imaging light in the image field.

An imaging optical system for a projection exposure system has at least one anamorphically imaging optical element. This allows a complete illumination of an image field in a first direction with a large object-side numerical aperture in this direction, without the extent of the reticle to be imaged having to be enlarged and without a reduction in the throughput of the projection exposure system occurring.