A method includes simulating diffraction in a transmission geometry of relativistic electron bunches from a crystallographic structure of a crystal thereby simulating diffraction of the relativistic electron bunches into a plurality of Bragg peaks. The method includes selecting a range of angles between a direction of propagation of the relativistic electron bunches and a normal direction of crystal including an angle at which a diffraction portion is maximized. The method includes sequentially accelerating a plurality of physical electron bunches to relativistic energies toward a physical crystal having the crystallographic structure and diffracting the plurality of physical electron bunches off the physical crystal at different angles and measuring the diffraction portion into the respective Bragg peak at the different angles. The method includes selecting a final angle based on the measured diffraction portion into the respective Bragg peak at the different angles and generating a pulse of light.

A cost-effective method for repairing reflective optical elements for EUV lithography. These optical elements (60) have a substrate (61) and a coating (62) that reflects at a working wavelength in the range between 5 nm and 20 nm and is damaged as a result of formation of hydrogen bubbles. The method includes: localizing a damaged area (63, 64, 65, 66) in the coating (62) and covering the damaged area (63, 64, 65, 66) with one or more materials having low hydrogen permeability by applying a cover element to the damaged area. The cover element is formed of a surface structure, a convex or concave surface, or a coating corresponding to the coating of the reflective optical element, or a combination thereof. The method is particularly suitable for collector mirrors (70) for EUV lithography. After the repair, the optical elements have cover elements (71, 72, 73).

A metal grid includes: a member which includes a curved principal surface; an anodic oxide film which is formed on the principal surface of the member, and a lattice structure which has an uneven shape periodically formed on the anodic oxide film. A production method for a metal grid includes: a step of forming a valve metal film on a principal surface of a member, a step of forming an anodic oxide film by performing an anodic oxidation treatment on the valve metal film while the principal surface is curved; and a step of forming a lattice structure with a periodic uneven shape on the anodic oxide film by forming an etching mask with a periodic opening on a surface of the anodic oxide film and etching the anodic oxide film through the opening.

Methods for the manufacture of extreme ultraviolet (EUV) mask blanks and production systems therefor are disclosed. A method for forming an EUV mask blank comprises forming a bilayer on a portion of a multi-cathode PVD chamber interior and then forming a multilayer stack of Si/Mo on a substrate in the multi-cathode PVD chamber.

An x-ray optical filter includes at least one x-ray optical mirror configured to receive a plurality of x-rays having a first x-ray spectrum with a first intensity as a function of energy in a predetermined solid angle range and to separate at least some of the received x-rays by multilayer reflection or total external reflection into reflected x-rays and non-reflected x-rays and to form an x-ray beam including at least some of the reflected x-rays and/or at least some of the non-reflected x-rays. The x-ray beam has a second x-ray spectrum with a second intensity as a function of energy in the solid angle range, the second intensity greater than or equal to 50% of the first intensity across a first continuous energy range at least 3 keV wide, the second intensity less than or equal to 10% of the first intensity across a second continuous energy range at least 100 eV wide.

An X-ray generator includes: a line X-ray source; a multilayer film mirror; and a side-by-side reflecting mirror including two concave mirrors joined together so as to share a join line. A cross section of a reflecting surface of the multilayer film mirror has a parabolic shape, and a focus of the parabolic shape is located at the line X-ray source. Cross sections of reflecting surfaces of the two concave mirrors of the side-by-side reflecting mirror each have a parabolic shape, and each of focuses of the parabolic shapes is located on a side opposite to the multilayer film mirror. An extended line of the join line of the side-by-side reflecting mirror passes through the multilayer film mirror and the line X-ray source as viewed in a plan view.

Extreme ultraviolet (EUV) mask blanks, methods for their manufacture and production systems therefor are disclosed. The EUV mask blanks comprise a substrate; a multilayer stack of reflective layers on the substrate; a capping layer on the multilayer stack of reflecting layers; and an absorber layer on the capping layer, the absorber layer made from iron and tellurium.

An example method for making a reticle includes providing an assembly. The assembly includes an extreme ultraviolet mirror and a cavity overlaying at least a bottom part of the extreme ultraviolet mirror. The method also includes at least partially filling the cavity with an extreme ultraviolet absorbing structure that includes a metallic material that includes an element selected from Ni, Co, Sb, Ag, In, and Sn, by forming the extreme ultraviolet absorbing structure selectively in the cavity.

A metal grid includes: a member which includes a curved principal surface; an anodic oxide film which is formed on the principal surface of the member, and a lattice structure which has an uneven shape periodically formed on the anodic oxide film. A production method for a metal grid includes: a step of forming a valve metal film on a principal surface of a member, a step of forming an anodic oxide film by performing an anodic oxidation treatment on the valve metal film while the principal surface is curved; and a step of forming a lattice structure with a periodic uneven shape on the anodic oxide film by forming an etching mask with a periodic opening on a surface of the anodic oxide film and etching the anodic oxide film through the opening.

Disclosed is a method of measuring focus performance of a lithographic apparatus, and corresponding patterning device and lithographic apparatus. The method comprises using the lithographic apparatus to print one or more first printed structures and second printed structures. The first printed structures are printed by illumination having a first non-telecentricity and the second printed structures being printed by illumination having a second non-telecentricity, different to said first non-telecentricity. A focus dependent parameter related to a focus-dependent positional shift between the first printed structures and the second printed structures on said substrate is measured and a measurement of focus performance based at least in part on the focus dependent parameter is derived therefrom.