Abstract: An EUV collector (24) serves for use in an EUV projection exposure apparatus for guiding EUV used light emanating from a source region of an EUV light source. The collector (24) has at least one reflection surface (30) that is curved to obtain a specified optical power. The collector (24) furthermore has at least one interchangeable reflection surface section (31i) and a holder (45) for holding the interchangeable reflection surface section (31i) in a collector recess (32) which is complementary to the interchangeable reflection surface section and is located in the EUV collector (24). The interchangeable reflection surface section (31i) is curved in accordance with the specified optical power. The outlay for testing collector materials and/or collector coating materials is reduced in the case of such an EUV collector.

Abstract: Method for avoiding a degradation of an optical element, wherein the optical element is arranged in a housing, comprising: a) determining a first degradation value; b) determining a second degradation value, wherein the first degradation value and the second degradation value are determined at different times; c) forming a degradation profile based on the first degradation value and the second degradation value; d) calculating a temporal development of the degradation profile; e) determining at least one predicted degradation value based on the calculated temporal development of the degradation profile; f) comparing the at least one predicted degradation value with a predefinable first limit degradation value; g) monitoring for a predefinable first deviation between the at least one predicted degradation value and the first limit degradation value; h) feeding a first decontamination medium into the interior if attainment of the predefinable first deviation is identified.

Abstract: A method of depositing a cover layer onto an optical element (M1) for reflection of EUV radiation. In the method, a cover layer containing phosphorus (P) is deposited onto the optical element (M1). The optical element (M1) in the course of deposition of the cover layer (35) is disposed in an interior (39) of a housing (36) of an EUV lithography system, and, for the deposition of the cover layer, phosphorus (P) is released from at least one phosphorus source (42, 43) disposed outside the interior (39) or within the interior (39). Also disclosed are an EUV lithography system and an optical element (M1) for reflecting EUV radiation.

Abstract: A multi-mirror array comprises a carrier structure and a multiplicity of mirror units arranged next to one another in a grid arrangement on the carrier structure. Each mirror unit comprises a base element and a mirror element. Each mirror element is mounted individually movably relative to the base element. Each mirror element has a mirror substrate, which, on a front surface facing away from the base element, bears a reflection coating, which can be designed for EUV radiation or for DUV radiation. The mirror surfaces are arranged next to one another to substantially fill the surface area. Between directly adjacent mirror elements there is a gap delimited by side surfaces of the adjoining mirror substrates to ensure a collision-free relative movement of the adjacent mirror elements.

Abstract: A method of depositing an outer layer (35) on a surface (36) of a reflective optical element (30) for the EUV wavelength range, wherein the depositing is effected in at least one macro cycle (37). The macro cycle (37) includes: at least partly depositing the outer layer (35) with an atomic layer deposition (ALD) process in at least one ALD cycle and partly back-etching the outer layer (35). Also disclosed is a reflective optical element (30) for the extreme ultraviolet (EUV) wavelength range which includes a surface (36) having an outer layer (35), wherein the outer layer (35) is deposited by the above-described method, and to an EUV lithography system having at least one such reflective optical element (30).

Abstract: A projection exposure apparatus (1) for semiconductor lithography, has a device for determining the concentration of atomic hydrogen in a plasma (29) in the region of an optical element (25, 25.1), wherein the device includes a sensor (32, 32.1, 32.2, 32.3, 32.4), In this case, the device includes a filter element (31, 31.1,31.2, 31.3, 31.4) arranged between the region of the plasma (29) and the sensor (32, 32.1, 32.2, 32.3, 32.4), wherein the filter element (31, 31.1,31.2, 31.3, 31.4) is configured to predominantly allow the passage of atomic hydrogen from the plasma (29) to the sensor (32, 32.1, 32.2, 32.3, 32.4).

Abstract: Method for avoiding a degradation of an optical element, wherein the optical element is arranged in a housing, comprising: a) determining a first degradation value; b) determining a second degradation value, wherein the first degradation value and the second degradation value are determined at different times; c) forming a degradation profile based on the first degradation value and the second degradation value; d) calculating a temporal development of the degradation profile; e) determining at least one predicted degradation value based on the calculated temporal development of the degradation profile; f) comparing the at least one predicted degradation value with a predefinable first limit degradation value; g) monitoring for a predefinable first deviation between the at least one predicted degradation value and the first limit degradation value; h) feeding a first decontamination medium into the interior if attainment of the predefinable first deviation is identified.