Abstract: An imaging optical system has a plurality of mirrors. These image an object field in an object plane into an image field in an image plane. In the imaging optical system, the ratio of a maximum angle of incidence of imaging light) on reflection surfaces of the mirrors and an image-side numerical aperture of the imaging optical system is less than 33.8°. This can result in an imaging optical system which offers good conditions for a reflective coating of the mirror, with which a low reflection loss can be achieved for imaging light when passing through the imaging optical system, in particular even at wavelengths in the EUV range of less than 10 nm.

Abstract: In some embodiments, a catoptric microlithgraphy projection optical system includes a plurality of reflective optical elements arranged to image radiation from an object field in an object plane to an image field in an image plane. The image field can have a size of at least 1 mm×1 mm. This optical system can have an object-image shift (OIS) of about 75 mm or less. Metrology and testing can be easily implemented despite rotations of the optical system about a rotation axis. Such a catoptric microlithgraphy projection optical system can be implemented in a microlithography tool. Such a microlithography tool can be used to produce microstructured components.

Abstract: An imaging optical system has a plurality of mirrors. These image an object field in an object plane into an image field in an image plane. In the imaging optical system, the ratio of a maximum angle of incidence of imaging light) on reflection surfaces of the mirrors and an image-side numerical aperture of the imaging optical system is less than 33.8°. This can result in an imaging optical system which offers good conditions for a reflective coating of the mirror, with which a low reflection loss can be achieved for imaging light when passing through the imaging optical system, in particular even at wavelengths in the EUV range of less than 10 nm.

Abstract: According to one exemplary embodiment, a photolithographic reduction projection catadioptric objective is provided and includes a first optical group (G1) and a second substantially refractive optical group (G2) more image forward than the first optical group (G1). The second optical group (G2) includes a number of lens elements (E4-E16) and has a negative overall magnifying power for providing image reduction. The first optical group (G1) has a folded geometry for producing a virtual image and the second optical group (G2) receives and reduces the virtual image to form an image with a numerical aperture of at least substantially (0.80).

Abstract: An objective for a microlithography projection system has at least one fluoride crystal lens. The effects of birefringence, which are detrimental to the image quality, are reduced if the lens axis of the crystal lens is oriented substantially perpendicular to the {100}-planes or {100}-equivalent crystallographic planes of the fluoride crystal. If two or more fluoride crystal lenses are used, they should have lens axes oriented in the (100)-, (111)-, or (110)-direction of the crystallographic structure, and they should be oriented at rotated positions relative to each other. The birefringence-related effects are further reduced by using groups of mutually rotated (100)-lenses in combination with groups of mutually rotated (111)- or (110)-lenses. A further improvement is also achieved by applying a compensation coating to at least one optical element of the objective.