An optical apparatus and a lithographic apparatus including the optical apparatus. The optical apparatus includes a substrate having an aperture for passing light; a transmissive optical element covering the aperture of the substrate; and an optical contact bond between the substrate and transmissive optical element, the optical contact bond being spaced from the aperture a sufficient distance such that stress forces in the transmissive optical element from the optical contact bond to the aperture are below an acceptable stress threshold. The optical contact bond geometry herein, for example, minimizes a contact area and provides a quasi-kinematic (near-exactly constrained) interface between the substrate and the optical element.

An illumination optical apparatus includes a plurality of birefringent members made of a birefringent material and arranged in an optical path on an incidence side of an optical integrator. The members change a polarization state of illumination light such that first and second rays of the illumination light are polarized in different directions on the pupil plane. The birefringent members are arranged such that an optical path length of the first ray in the birefringent material is different from an optical path length of the second ray in the birefringent material, and are arranged so as to change the polarization state of the illumination light incident on the plurality of the birefringent members in a linear polarization state having a substantially single polarization direction such that each of the first and second rays is polarized in a substantially circumferential direction about the optical axis on the pupil plane.

A compound lens assembly and method for making a compound lens assembly useful for deep ultraviolet lithography are described. The compound lens assembly includes a first lens component having an optical surface bonded to an optical surface of a second lens component. The bonding at the interface can be achieved using a hydroxide catalysis bonding technique. The compound lens assembly and process for making same solve problems relating to constringence and/or inherent birefringence known for conventional optical elements used in deep ultraviolet lithography or inspection of wafers or reticles in the DUV.

A reflective optical element for the extreme ultraviolet (EUV) wavelength range having a multi-layer system extending over an area on a substrate. The system includes layers (54, 55′) made of at least two different materials with different real parts of the refractive index in the EUV arranged alternately. A layer of one of the two materials forms a stack with the layer or layers arranged between this layer and the nearest layer of the same material with increasing distance from the substrate. In at least one stack (53′), the material of the layer (55′) with the lower real part of the refractive index and/or the material of the layer (54) with the larger real part of the refractive index is a combination (551, 552) made of at least two substances.

An optical system, in particular for microlithography, includes a beam splitter, which has at least one light entry surface. The beam splitter is arranged in the optical system so that the angles of incidence with respect to the surface normal which occur at the light entry surface during operation of the optical system lie in the range of 45°±5°. The beam splitter is produced in the [110] crystal cut.

An optical system, in particular for microlithography, includes a beam splitter, which has at least one light entry surface. The beam splitter is arranged in the optical system so that the angles of incidence with respect to the surface normal which occur at the light entry surface during operation of the optical system lie in the range of 455. The beam splitter is produced in [110] the crystal cut.

A compound lens assembly and method for making a compound lens assembly useful for deep ultraviolet lithography are described. The compound lens assembly includes a first lens component having an optical surface bonded to an optical surface of a second lens component. The bonding at the interface can be achieved using a hydroxide catalysis bonding technique. The compound lens assembly and process for making same solve problems relating to constringence and/or inherent birefringence known for conventional optical elements used in deep ultraviolet lithography or inspection of wafers or reticles in the DUV.

A microlithography optical system includes a projection objective and an illumination system that includes a temperature compensated polarization-modulating optical element. The temperature compensated polarization-modulating optical element includes a first polarization-modulating optical element of optically active material, the first polarization-modulating optical element having a first specific rotation with a sign. The temperature compensated polarization-modulating optical element includes also includes a second polarization-modulating optical element of optically active material, the second polarization-modulating optical element having a second specific rotation with a sign opposite to the sign of the first specific rotation.

The disclosure concerns an illumination system of a microlithographic projection exposure apparatus. The illumination system includes a mirror arrangement which has a plurality of mirror units and at least one element arranged in front of the mirror arrangement in the light propagation direction to produce at least two different states of polarization incident on different mirror units. The mirror units are displaceable independently of each other for altering an angle distribution of the light reflected by the mirror arrangement.

A reflective optical element for the extreme ultraviolet (EUV) wavelength range having a multi-layer system extending over an area on a substrate. The system includes layers (54, 55) made of at least two different materials with different real parts of the refractive index in the EUV arranged alternately. A layer of one of the two materials forms a stack with the layer or layers arranged between this layer and the nearest layer of the same material with increasing distance from the substrate. In at least one stack (53), the material of the layer (55) with the lower real part of the refractive index and/or the material of the layer (54) with the larger real part of the refractive index is a combination (551, 552) made of at least two substances.