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.

An inspection system includes a projection system including a radiation source configured to transmit an illumination beam along an illumination path and an aperture stop configured to select a portion of the illumination beam. The inspection system also includes an aperture stop that selects a portion of the illumination beam and an optical system that transmits the selected portion of the illumination beam towards an object and transmit a signal beam scattered from the object. The inspection system also includes a detector that detects the signal beam.

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 illumination optical apparatus illuminates an object with illumination light. The illumination optical apparatus includes an optical integrator arranged in an optical path of the illumination light; and a polarization modulating member which modulates a polarization of the illumination light, the polarization modulating member being made of an optical material with optical activity and being arranged in the optical path on an incidence side of the optical integrator such that a direction of an optic axis of the optical material is coincident with a direction of an optical axis of the illumination optical apparatus. The polarization modulating member has a thickness profile varying with respect to azimuthal positions about the optical axis.

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.

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.

Projection exposure methods, systems, sub-systems and components are disclosed. Methods can include performing a first exposure to image a first sub-pattern of the pattern, where the first sub-pattern includes a plurality of first features extending in a first direction and spaced apart essentially periodically at a predominant periodicity length P in a second direction perpendicular to the first direction. The first exposure can be performed using a multipolar illumination mode that includes at least one substantially dipolar intensity distribution having two illumination poles positioned on a pole orientation axis substantially parallel to the second direction and spaced apart from each other.

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 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.

Projection exposure methods, systems, sub-systems and components are disclosed. Methods can include performing a first exposure to image a first sub-pattern of the pattern, where the first sub-pattern includes a plurality of first features extending in a first direction and spaced apart essentially periodically at a predominant periodicity length P in a second direction perpendicular to the first direction. The first exposure can be performed using a multipolar illumination mode that includes at least one substantially dipolar intensity distribution having two illumination poles positioned on a pole orientation axis substantially parallel to the second direction and spaced apart from each other.