A cloaking device includes an object-side, an image-side, an object-side curved cloaking region (CR) boundary having an outward facing mirror surface and an inward facing surface, and an image-side curved CR boundary an outward facing mirror surface and an inward facing surface. A cloaked region is bounded by the inward facing surfaces of the object-side curved CR boundary and the image-side curved CR boundary. At least one exterior boundary with an inward facing mirror surface is spaced apart from the object-side curved CR boundary and the image-side curved CR boundary. Light from an object positioned on the object-side of the cloaking device and obscured by the cloaked region is redirected around the cloaked region to form an image of the object on the image-side of the cloaking device such that the light from the object appears to pass through the CR.

A projection lens of an EUV-lithographic projection exposure system with at least two reflective optical elements each comprising a body and a reflective surface for projecting an object field on a reticle onto an image field on a substrate if the projection lens is exposed with an exposure power of EUV light, wherein the bodies of at least two reflective optical elements comprise a material with a temperature dependent coefficient of thermal expansion which is zero at respective zero cross temperatures, and wherein the absolute value of the difference between the zero cross temperatures is more than 6K.

In a method for three-dimensionally measuring a 3D aerial image in the region around an image plane during the imaging of a lithography mask, which is arranged in an object plane, a selectable imaging scale ratio in mutually perpendicular directions (x, y) is taken into account. For this purpose, an electromagnetic wavefront of imaging light is reconstructed after interaction thereof with the lithography mask. An influencing variable that corresponds to the imaging scale ratio is included. Finally, the 3D aerial image measured with the inclusion of the influencing variable is output. This results in a measuring method with which lithography masks that are optimized for being used with an anamorphic projection optical unit during projection exposure can also be measured.

An imaging optical unit serves within a metrology system for examining a lithography mask. The lithography mask can be arranged in an object field of the imaging optical unit. The object field is defined by two mutually perpendicular object field coordinates. The imaging optical unit has an aperture stop of which the aspect ratio in the direction of the two object field coordinates differs from 1. This results in an imaging optical unit which can be used for the examination of lithography masks that are designed for projection exposure with an anamorphic projection optical unit.

An imaging optical system has a plurality of mirrors which image an object field in an object plane in an image field in an image plane. The imaging optical system has a pupil obscuration. The last mirror in the beam path of the imaging light between the object field and the image field has a through-opening for the passage of the imaging light. A penultimate mirror of the imaging optical system in the beam path of the imaging light between the object field and the image field has no through-opening for the passage of the imaging light. The result is an imaging optical system that provides a combination of small imaging errors, manageable production and a good throughput for the imaging light.

A projection lens of an EUV-lithographic projection exposure system with at least two reflective optical elements each comprising a body and a reflective surface for projecting an object field on a reticle onto an image field on a substrate if the projection lens is exposed with an exposure power of EUV light, wherein the bodies of at least two reflective optical elements comprise a material with a temperature dependent coefficient of thermal expansion which is zero at respective zero cross temperatures, and wherein the absolute value of the difference between the zero cross temperatures is more than 6K.

A method and a device for producing an optical component having at least three monolithically arranged optical functional surfaces and an optical component are disclosed. The method includes calculating a continuous surface composite, which includes the first optical functional surface and the second optical functional surface, producing the continuous surface composite, which contains the first and second optical functional surfaces in a defined shape and a relative position to one another, on the first side of the optical component through machining by a machine tool, producing at least one reference surface arranged outside the optical functional surfaces on the optical component or on a mount and having a defined positional relation to the optical functional surfaces through machining by the machine tool and repositioning the optical component in such a way that the second side of the optical component is machined with the machine tool, wherein the at least one reference surface serves as a contact surface or mounting surface.

A projection lens of an EUV-lithographic projection exposure system with at least two reflective optical elements each comprising a body and a reflective surface for projecting an object field on a reticle onto an image field on a substrate if the projection lens is exposed with an exposure power of EUV light, wherein the bodies of at least two reflective optical elements comprise a material with a temperature dependent coefficient of thermal expansion which is zero at respective zero cross temperatures, and wherein the absolute value of the difference between the zero cross temperatures is more than 6K.

A reflective imager design that is telecentric in image space, or equivalently telecentric at an image plane, or equivalently having an exit pupil located substantially at infinity, while also having an external entrance pupil and a high throughput or fast optical speed is described.

An image forming optical system 1 includes, in order from an enlargement side, a first optical system 111 having a reflecting surface, and a second optical system 112 having a refracting surface. The image forming optical system 1 is configured to form an intermediate image 104 between the first optical system 111 and the second optical system 112. The first optical system 111 includes, in order from the enlargement side, a first reflecting group 113 having at least one reflecting surface having negative power, and a second reflecting group 114 having a plurality of reflecting surfaces 116 and 117 having positive power. The at least one reflecting surface having negative power includes a reflecting surface 115 closest to the enlargement side in the first reflecting group 113. An absolute value of power of the reflecting surface 115 is smallest in the first optical system 111.