A method for operating an EUV lithography apparatus (1) with at least one vacuum housing (27) for at least one reflective optical element (12) includes operating the EUV lithography apparatus in an exposure operating mode (B), in which EUV radiation (5) is radiated into the vacuum housing, wherein a reducing plasma is generated at a surface (12a) of the reflective optical element in response to an interaction of the EUV radiation with a residual gas present in the vacuum housing. After an exposure pause, in which no EUV radiation is radiated into the vacuum housing, and before renewed operation of the EUV lithography apparatus in the exposure operating mode (B), the EUV lithography apparatus is operated in a recovery operating mode, in which oxidized contaminants at the surface of the reflective optical element are reduced in order to recover a transmission of the EUV lithography apparatus before the exposure pause.

A doubly bent X-ray spectroscopic device (1) according to the present invention includes: a glass plate (3) which is deformed into a shape having a doubly bent surface by being sandwiched between a doubly curved convex surface (21a) of a convex forming die (21) and a doubly curved concave surface (22a), of a concave forming die (22), that matches the doubly curved convex surface (21a), and being heated to a temperature of 400° C. to 600° C.; and a reflection coating (5) configured to reflect X-rays, which is formed on a concave surface (3a) of the deformed glass plate (3 ).

A device (20) for detecting a temperature on a surface (15) of an optical element (14) for semiconductor lithography. The device includes an optical element (14) having a face (16) irradiated with electromagnetic radiation (7, 8, 43), a temperature recording device (21), and a temperature controlled element (22) configured to be temperature-controlled and arranged so that the predominant proportion of the intensity of the thermal radiation (25.2) detected by the temperature recording device and reflected by reflection at the surface of the optical element is emitted by the temperature-controlled element.

Also disclosed are an installation (1) for producing a surface (15) of an optical element (14) for semiconductor lithography and a method for producing a surface (15) of an optical element (14) of a projection exposure apparatus (30), wherein the surface is temperature-controlled and the surface temperature is detected during the temperature control.

A reflector comprising a hollow body having an interior surface defining a passage through the hollow body, the interior surface having at least one optical surface part configured to reflect radiation and a supporter surface part, wherein the optical surface part has a predetermined optical power and the supporter surface part does not have the predetermined optical power. The reflector is made by providing an axially symmetric mandrel; shaping a part of the circumferential surface of the mandrel to form at least one inverse optical surface part that is not rotationally symmetric about the axis of the mandrel; forming a reflector body around the mandrel; and releasing the reflector body from the mandrel whereby the reflector body has an optical surface defined by the inverse optical surface part and a supporter surface part defined by the rest of the outer surface of the mandrel.

Extreme ultraviolet (EUV) mask blanks, production systems therefor, and methods of reducing roughness are disclosed. The EUV mask blanks comprise a multilayer reflective stack on a substrate comprising a plurality of pairs of alternating layers comprising a first layer and a second layer, the first layer including a first element selected from the group consisting of Si, B, Al, Mg, Zr, Ba, Nb, Ti, Gd, Y, and Ca; and the second layer including a second element selected from the group consisting of Ru, Mo, Ta, Sb, Tc, Nb, Ir, Pt, and Pd. Some EUV mask blanks described herein include interface layer between the first layer and the second layer, the interface layer including an interface element selected from the group consisting of Si, B, C, Al, Mo, and Ru.

A microscope system for flexibly, efficiently and quickly inspecting patterns and defects on extreme ultraviolet (EUV) lithography photomasks. The system includes a stand-alone plasma-based EUV radiation source with an emission spectrum with a freestanding line emission in the spectral range from 12.5 nm to 14.5 nm has a relative bandwidth of λ/Δλ>1000, means for the broadband spectral filtering λ/Δλ<50 for selecting the dominant freestanding emission line, means for suppressing radiation with wavelengths outside of the EUV spectral region, zone plate optics for magnified imaging of the object with a resolution which corresponds to the width of an outermost zone of the zone plate, a numerical aperture corresponding to more than 1000 zones, and a EUV detector array for capturing the patterned object.

A method of making a mirror for use with extreme ultraviolet (EUV) or X-ray radiation is disclosed. The method includes: a) providing an optical element having a curved mirror surface, wherein the curved mirror surface comprises localized defects that degrade performance of the curved mirror surface; b) spin-coating the curved mirror surface with a material to cover at least some of the defects; and c) curing the spin-coated material on the curved mirror surface to reduce the number of defects and improve the performance of the curved mirror surface. Also disclosed is a mirror made by the method.

An EUV collector mirror for an extreme ultra violet (EUV) radiation source apparatus includes an EUV collector mirror body on which a reflective layer as a reflective surface is disposed, a heater attached to or embedded in the EUV collector mirror body and a drain structure to drain melted metal from the reflective surface of the EUV collector mirror body to a back side of the EUV collector mirror body.

A multilayer mirror for reflecting Extreme Ultraviolet (EUV) radiation and a method for producing the same are disclosed. In an embodiment a multilayer mirror includes a layer sequence having a plurality of alternating first layers and second layers, the first layers including lanthanum or a lanthanum compound and the second layers including boron, wherein the second layers are doped with carbon, and wherein a molar fraction of carbon in the second layers is 10% or less.

A reflective film coated substrate includes a substrate having two main surfaces opposite to each other and end faces connected to outer edges of the two main surfaces; and a reflective film formed on one of the main surfaces and extending onto at least part of the end faces. The reflective film on the main surface has a multilayer structure including low refractive index layers and high refractive index layers alternately formed. The reflective film which extends onto the end faces has a single-layer structure containing a first element higher in content than any other element in the low refractive index layers and a second element higher in content than any other element in the high refractive index layers.