A metrology system includes a beam splitter and first and second sensors. The beam splitter splits scattered radiation scattered by a target into first and second portions of radiation. The first sensor receives the first portion. The second sensor receives the second portion after the second portion propagates along a path that includes a wedge system comprising a first wedge configured to diverge the second portion.

An overlay measurement apparatus that can quickly measure an overlay error between layers with a large height difference is provided. The overlay measurement apparatus measures an error between a first overlay mark and a second overlay mark formed in a pair on different layers of a wafer. The overlay measurement apparatus includes an imaging system configured to acquire alignment images of a pair of first and second overlay marks at a plurality of focus positions, and a controller communicatively coupled to the imaging system. The overlay measurement apparatus can rapidly and accurately measure an overlay error between layers with a large height difference.

An optical metrology system may include an overlay metrology tool for characterizing an overlay target on a sample, where the overlay target includes first-direction periodic features in a first set of layers of the sample, and second-direction periodic features in a second set of layers of the sample. The overlay metrology tool may simultaneously illuminate the overlay target with first illumination beams and second illumination beams and may further generate images of the overlay target based on diffraction of the first illumination beams and the second illumination beams by the overlay target, where diffraction orders of the first illumination beams contribute to resolved image formation of only the first-direction periodic features, and where diffraction orders of the second illumination beams contribute to resolved image formation of only the second-direction periodic features. The system may further generate overlay measurements along the first and second measurement directions based on the images.

A system of measuring an image of a pattern in a high NA scanning-type extreme ultra-violet (EUV) mask is disclosed. The system may include a light source generating an EUV light; an toroidal mirror; an flat mirror allowing light, which is reflected by the toroidal mirror, to be incident into the mask; an beam splitter; a light detection part; an anamorphic zone-plate lens focusing a transmitted portion of a light emitted from the beam splitter on the mask; a stage; and an anamorphic photo sensor, which is configured to measure an energy of a reflected portion of the coherent EUV light, is composed of a detector array, and has different sizes from each other in horizontal and vertical directions of an incidence surface of the detector array.

An overlay metrology system may scan a sample including inverted Moire structure pairs along a scan direction, include an illumination sub-system to illuminate first and second Moire structures of one of an inverted Moire structure pair with common mutually coherent illumination beam distributions, and include an objective lens to capture at least +/-1 diffraction orders from sample, where a first pupil plane includes overlapping distributions of the collected light with an interference pattern associated with relative wavefront tilt. The system may also include a diffractive element in the first pupil plane, where one diffraction order associated with the first Moire structure and one diffraction order associated with the second Moiré structure overlap at a common overlap region in a field plane, and a collection field stop located in the field plane to pass light in the common overlap region and block remaining light and remove the relative wavefront tilt.

An optical metrology system may include an overlay metrology tool for characterizing an overlay target on a sample, where the overlay target includes first-direction periodic features in a first set of layers of the sample, and second-direction periodic features in a second set of layers of the sample. The overlay metrology tool may simultaneously illuminate the overlay target with first illumination beams and second illumination beams and may further generate images of the overlay target based on diffraction of the first illumination beams and the second illumination beams by the overlay target, where diffraction orders of the first illumination beams contribute to resolved image formation of only the first-direction periodic features, and where diffraction orders of the second illumination beams contribute to resolved image formation of only the second-direction periodic features. The system may further generate overlay measurements along the first and second measurement directions based on the images.

An overlay measurement apparatus that can quickly measure an overlay error between layers with a large height difference is provided. The overlay measurement apparatus measures an error between a first overlay mark and a second overlay mark formed in a pair on different layers of a wafer. The overlay measurement apparatus includes an imaging system configured to acquire alignment images of a pair of first and second overlay marks at a plurality of focus positions, and a controller communicatively coupled to the imaging system. The overlay measurement apparatus can rapidly and accurately measure an overlay error between layers with a large height difference.

A shadow mask includes a mask including one surface, another surface, and an opening that passes from one surface to the other, and a shutter provided on the one surface of the mask and configured to adjust a size of the opening, wherein the shutter is configured to move from an edge to a center of the opening to adjust the size of the opening, and the shadow mask is applied in manufacturing a blank mask for a semiconductor lithography process.

Disclosed is a metrology apparatus and method for measurement of a diffractive structure on a substrate. The metrology apparatus comprises a radiation source operable to provide first radiation for excitation of the diffractive structure such that high harmonic second radiation is generated from said diffractive structure and/or substrate; and a detection arrangement operable to detect said second radiation, at least a portion of which having been diffracted by said diffractive structure.

Disclosed is an optical imaging system, and associated method, comprising a stage module configured to support an object such that an area of the object is illuminated by an illumination beam; an objective lens configured to collect at least one signal beam, the at least one signal beam originating from the illuminated area of the object; an image sensor configured to capture an image formed by the at least one signal beam collected by the objective lens; and a motion compensatory mechanism operable to compensate for relative motion of the stage module with respect to the objective lens during an image acquisition. The motion compensatory mechanism causes a compensatory motion of one or more of: said objective lens or at least one optical element thereof; said image sensor; and/or an optical element comprised within a detection branch and/or illumination branch of the optical imaging system.