A method for restoring an illumination system installed in an EUV apparatus is provided.

An apparatus comprises an array of light emitting diodes (LEDs), each LED in the array having an asymmetric optical characteristic. The asymmetric optical characteristic of a first subset of LEDs in the array is oriented at an angle of 90°, 180°, or 270° with respect to the asymmetrical optical characteristic of a second subset of LEDs in the array. The apparatus may be the array of LEDs or an illumination system comprising a light source comprising the array of LEDs. Methods of manufacturing the apparatus are also provided.

An optical lithography system is provided, comprising: a polygonal structure having a central region and a central axis; an UV light source detachably disposed in the central region or at an end of the polygonal structure; a light parallelizer positioned in the polygonal structure for creating substantially parallel light rays from the UV light source exiting the polygonal structure before reaching a lithography target adjacent to an exit of the polygonal structure, which includes at least three mirrors arranged such that the first mirror receives incident light from the UV light source and reflects thereof from the first mirror towards the second mirror, the second mirror receiving the reflected light as a second incident light and reflecting thereof from the second mirror towards the third mirror to create a spiral light path from the UV light source to the lithography target with substantially parallel light incident on the lithography target.

An optical lithography system is provided, comprising: a polygonal structure having a central region and a central axis; an UV light source detachably disposed in the central region or at an end of the polygonal structure; a light parallelizer positioned in the polygonal structure for creating substantially parallel light rays from the UV light source exiting the polygonal structure before reaching a lithography target adjacent to an exit of the polygonal structure, which includes at least three mirrors arranged such that the first mirror receives incident light from the UV light source and reflects thereof from the first mirror towards the second mirror, the second mirror receiving the reflected light as a second incident light and reflecting thereof from the second mirror towards the third mirror to create a spiral light path from the UV light source to the lithography target with substantially parallel light incident on the lithography target.

An optical assembly includes an optical element (13), configured in particular for the reflection of EUV radiation (4), and a protective element (30) for protecting a surface (31) of the optical element (13, 14) from contaminating substances (P). The protective element (30) has a membrane (33a-c) and a frame (34) on which the membrane (33a-c) is mounted. The membrane is formed by a plurality of membrane segments (33a, 33b, 33c) which respectively protect a partial region (T) of the surface (31) of the optical element (13) from the contaminating substances (P). The optical assembly can form part of an overall optical arrangement, for example an EUV lithography system.

A method for producing a reflecting optical element for a projection exposure apparatus (1). The element has a substrate (30) with a substrate surface (31), a protection layer (38) and a layer partial system (39) suitable for the EUV wavelength range. The method includes: (a) measuring the substrate surface (31), (b) irradiating the substrate (30) with electrons (36), and (c) tempering the substrate (30). Furthermore, an associated reflective optical element for the EUV wavelength range, a projection lens with a mirror (18, 19, 20) as reflective optical element, and a projection exposure apparatus (1) including such a projection lens.

An illumination optical unit for EUV projection lithography serves for obliquely illuminating an illumination field, in which an object field of a downstream imaging catoptric optical unit and a reflective object to be imaged can be arranged. A pupil generating device of the illumination optical unit is embodied so that an illumination pupil results, which brings about a dependency of an imaging telecentricity against a structure variable of the object to be imaged. This dependency is such that a dependency of the imaging telecentricity against the structure variable of the object to be imaged on account of interaction of the oblique illumination with structures of the object to be imaged is at least partly compensated for. An optical system for EUV projection lithography also has an imaging catoptric optical unit alongside an illumination optical unit and can additionally have a wavefront manipulation device.

A diffuser system (100) and method for optically diffusing a light beam (L1,L2). At least two transmissive diffuser windows (11,21) are provided. The diffuser windows (11,21) are arranged to sequentially diffuse the light beam (L1,L2) transmitted there through. The diffuser system (100) is configured to continuously rotate the diffuser windows (11,21) at an angular velocity (ω1,ω2) for homogenizing a diffusive pattern of the transmitted light beam (L1,L2). The diffuser windows (11,21) are configured to rotate around distinct rotation axes (C1,C2). The distinct rotation axes (C1,C2) are parallel and offset with respect to each other by a radial center distance (d12). A rotating subarea of the first diffuser window (11) partially overlaps a rotating subarea of the second rotating diffuser window (12) The partially overlapping rotating subareas define a beam window (W12) for homogenizing and diffusing the transmitted light beam (L1,L2).

A projection exposure apparatus for semiconductor lithography has a connecting element for connecting a component of the apparatus to a supporting cooling structure of the apparatus. The connecting element has a receiving region for receiving the component, and the connecting element has a foot region for connecting the connecting element to the supporting cooling structure. At least one joint is arranged between the receiving and foot regions, and at least one heat conducting element is arranged between the receiving and foot regions. The heat conducting element is soft in the actuation direction of the joint and has a stiffness perpendicularly to the actuation direction of the joint that is at least twice as large as in the actuation direction of the joint.

An illumination optical unit for projection lithography illuminates an object field. The illumination optical unit has an optical rod with an entrance area and an exit area for illumination light. The optical rod is configured so that the illumination light is mixed and homogenized at lateral walls of the optical rod by multiple in-stances of total internal reflection. At least one correction area serves to correct a field dependence of an illumination angle distribution when illuminating the object field. The correction area is disposed in the region of the exit area of the optical rod. This can result in an illumination optical unit, in which an unwanted field dependence of a specified illumination angle distribution is reduced or entirely avoided, even in the case of illumination angle distributions with illumination angles deviating extremely from a normal incidence on the object field.