A target for generating x-rays includes at least one substrate including a first material and a plurality of discrete structures including at least one second material configured to generate x-rays in response to electron bombardment. The discrete structures are distributed across a first surface of the at least one substrate in an array pattern function A that has a corresponding function B such that a combination operation of the array pattern function A with the corresponding function B generates a resultant function C comprising a first portion with a single peak and a substantially flat second portion surrounding the first portion. The combination operation includes a cross-correlation operation or a convolution operation

A method of inspection for defects on a substrate, such as a reflective reticle substrate, and associated apparatuses. The method includes performing the inspection using inspection radiation obtained from a high harmonic generation source and having one or more wavelengths within a wavelength range of between 20 nm and 150 nm. Also, a method including performing a coarse inspection using first inspection radiation having one or more first wavelengths within a first wavelength range; and performing a fine inspection using second inspection radiation having one or more second wavelengths within a second wavelength range, the second wavelength range comprising wavelengths shorter than the first wavelength range.

Disclosed herein is an apparatus comprising: a radiation absorption layer comprising an electrode; a counter configured to register a number of radiation particles absorbed by the radiation absorption layer; a controller configured to start a time delay from a time at which an absolute value of an electrical signal on the electrode equals or exceeds an absolute value of a first threshold; wherein the controller is configured to cause the number registered by the counter to change, in response to the absolute value of the electrical signal equaling or exceeding an absolute value of a second threshold during the time delay.

Disclosed herein is an apparatus for electromagnetic x-ray control. The apparatus comprises a thermionic filament, positioned at a first end of a micro-focus x-ray tube and configured to generate an electron stream. The apparatus also comprises an x-ray generation target, positioned within the micro-focus x-ray tube at a second end of the micro-focus x-ray tube, opposite the first end, to receive the electron stream and to generate x-rays in response to the electron stream impinging on the x-ray generation target. The apparatus further comprises an electromagnetic field element, configured to generate an electromagnetic field that receives the electron stream and operable to vary the electromagnetic field to redirect the electron stream, within the micro-focus x-ray tube, to impinge on the x-ray generation target at variable locations on the x-ray generation target. Each one of the variable locations corresponds to a different one of multiple variations of the electromagnetic field.

The present teaching relates to methods, systems, and apparatus for X-ray imaging with a detector capable of resolving photon energy. In one example, an X-ray microscope is disclosed. The X-ray microscope comprises an X-ray source and a detector. The X-ray source is configured for irradiating X-ray to a sample. The detector is configured for: detecting X-ray photons from the irradiated X-ray, determining energy of each of the detected X-ray photons, and generating an image of the sample based on detected X-ray photons that have energies in a predetermined range.

A method and system are disclosed for producing an x-ray image of a sample using a lamella-shaped target to improve the usual tradeoff between imaging resolution and image acquisition time. A beam of electrons impacts the lamella-shaped target normal to the narrower dimension of the lamella which then determines the virtual source size along that axis. For low-energy x-ray generation, the small electron penetration depth parallel to the wider dimension of the lamella determines the virtual source size along that axis. Conductive cooling of the target is improved over post targets with the same imaging resolution. The lamella-shaped target is long enough to ensure that the electron beam does not impact the support structure which would degrade the imaging resolution. Target materials may be selected from the same metals used for bulk or post targets, including tungsten, molybdenum, titanium, scandium, vanadium, silver, or a refractory metal.

A method and system are disclosed for producing an x-ray image of a sample using a lamella-shaped target to improve the usual tradeoff between imaging resolution and image acquisition time. A beam of electrons impacts the lamella-shaped target normal to the narrower dimension of the lamella which then determines the virtual source size along that axis. For low-energy x-ray generation, the small electron penetration depth parallel to the wider dimension of the lamella determines the virtual source size along that axis. Conductive cooling of the target is improved over post targets with the same imaging resolution. The lamella-shaped target is long enough to ensure that the electron beam does not impact the support structure which would degrade the imaging resolution. Target materials may be selected from the same metals used for bulk or post targets, including tungsten, molybdenum, titanium, scandium, vanadium, silver, or a refractory metal.

The invention utilizes one exposure without moving parts to provide multiple x-ray views of an object. It relies on a 3D detector, which can be a stack of film plates, and a specified focusing x-ray optic. The x-ray optic, discussed below, allows collection of x-rays from a localized volume, just like an ordinary optical lens, and the stacked film plate, or other 3D detector design, allows collection of the multiple focal plane information from one line of sight.

The invention utilizes one exposure without moving parts to provide multiple x-ray views of an object. It relies on a 3D detector, which can be a stack of film plates, and a specified focusing x-ray optic. The x-ray optic, discussed below, allows collection of x-rays from a localized volume, just like an ordinary optical lens, and the stacked film plate, or other 3D detector design, allows collection of the multiple focal plane information from one line of sight.

An optical system (OS) for focusing a beam of radiation (B) on a region of interest in a metrology apparatus is described. The beam of radiation (B) comprises radiation in a soft X-ray or Extreme Ultraviolet spectral range. The optical system (OS) comprises a first stage (S1) for focusing the beam of radiation at an intermediate focus region. The optical system (OS) comprises a second stage (S2) for focusing the beam of radiation from the intermediate focus region onto the region of interest. The first and second stages each comprise a Kirkpatrick-Baez reflector combination. At least one reflector comprises an aberration-correcting reflector.