An extreme ultraviolet light generation system includes a chamber including a first region; a target supply unit supplying a target to the first region; a laser device outputting pulse laser light; an optical system including an optical element to guide the pulse laser light to the first region; an irradiation position adjustment mechanism adjusting a laser irradiation position; an EUV light concentrating mirror arranged such that the pulse laser light passes outside the EUV light concentrating mirror and is guided to the first region; a plurality of EUV sensors measuring radiation energies of the EUV light radiated from the first region in mutually different radiation directions, and having a geometric centroid located at a position away from the optical axis in a direction toward the EUV light concentrating mirror; and a processor controlling the irradiation position adjustment mechanism as setting a target irradiation position of the pulse laser light.

An illumination system for a metrology apparatus that can achieve illumination spatial profile flexibility, high polarization extinction ratio, and high contrast. The illumination system includes a polarizing beam splitter (PBS), an illumination mode selector (IMS), and a reflective spatial light modulator (SLM). The PBS divides an illumination beam into sub-beams. The IMS has a plurality of apertures that transmits at least one sub-beam and may be arranged in multiple illumination positions corresponding to illumination modes. A pixel array of the reflective SLM and reflects a portion of the sub-beam transmitted by the IMS back to the IMS and PBS. The PBS, IMS, SLM collectively generates a complex amplitude or intensity spatial profile of the transmitted sub-beam.

A dark field metrology device includes an objective lens arrangement and a zeroth order block to block zeroth order radiation. The objective lens arrangement directs illumination onto a specimen to be measured and collects scattered radiation from the specimen, the scattered radiation including zeroth order radiation and higher order diffracted radiation. The dark field metrology device is operable to perform an illumination scan to scan illumination over at least two different subsets of the maximum range of illumination angles; and simultaneously perform a detection scan which scans the zeroth order block and/or the scattered radiation with respect to each other over a corresponding subset of the maximum range of detection angles during at least part of the illumination scan.

An exposure apparatus for exposing a plurality of shot regions on a substrate includes a projection optical system, a drive mechanism configured to drive the substrate, a detector configured to detect a surface height of the substrate, and a controller configured to control the drive mechanism based on an output of the detector. The projection optical system is configured to project a pattern of an original to an exposure region in an image plane of the projection optical system. A detection region of the detector is larger than the exposure region. The controller is configured to control, based on an output of the detector obtained when a first shot region of the plurality of shot regions is arranged in the exposure region, driving of the substrate, by the drive mechanism, for exposing a second shot region of the plurality of shot regions.

A measuring device includes a light source that irradiates a measurement spot on a wafer formed with memory holes and slits with a multi-wavelength light, a first imaging unit that acquires a first pupil plane intensity distribution image of reflected light from the measurement spot, a second imaging unit that acquires a second pupil plane intensity distribution image of the reflected light, and a detection unit that analyzes the second pupil plane intensity distribution image to measure overlay. The measuring device includes an overlay analysis unit that acquires the first and second pupil plane intensity distribution images while moving a position of the measurement spot and selects a measurement spot not including the slit based on the first pupil plane intensity distribution image, and uses the overlay obtained by analyzing the second pupil plane intensity distribution image of the selected measurement spot as the overlay of the memory hole and a slit.

An overlay metrology system may include illumination sources configured to generate one or more pairs of mutually coherent illumination beams and illumination optics to direct the pairs of illumination beams to an overlay target at common altitude incidence angles and symmetrically opposed azimuthal incidence angles, where the overlay target includes two or more grating structures distributed along one or more measurement directions. The system may further include imaging optics to image the overlay target onto detectors when implementing the metrology recipe, where an image of a particular one of the two or more grating structures is generated exclusively with a single non-zero diffraction order of light from each of the illumination beams within the particular one of the pairs of illumination beams. The system may further include a controller to determine overlay measurements based on images of the overlay target.

A target supply device is configured to supply a liquid state target substance including tin to a concentration position of laser light to generate EUV light. The target supply device includes a tank configured to contain the target substance; and a nozzle communicating with an inside of the tank, and having a nozzle hole through which the target substance passes. Here, an uneven structure is formed on a surface of the nozzle provided with the nozzle hole and facing the concentration position and exhibits tin repellency larger than tin repellency exhibited by a material of the surface.

A method of measuring an overlay or focus parameter from a target and associated metrology apparatus. The method includes configuring measurement radiation to obtain a configured measurement spectrum of the measurement radiation by: imposing an intensity weighting on individual wavelength bands of the measurement radiation such that the individual wavelength bands have an intensity according to the intensity weighting, the intensity weighting being such that a measured value for the overlay or focus parameter is at least partially corrected for the effect of target imperfections; and/or imposing a modulation on a measurement spectrum of the measurement radiation. The configured measurement radiation is used to measure the target. A value for the overlay or focus parameter is determined from scattered radiation resultant from measurement of the target.

An overlay metrology system may include an objective lens, illumination optics to illuminate an overlay target including a first grating with a first pitch on a first sample layer and a second grating with a second pitch on a second sample layer, where the first and second sample layers are separated by a layer separation distance greater than a depth of field of the objective lens. The system may further include collection optics with a radially-varying defocus distribution to compensate for the layer separation distance such that the first and second gratings are simultaneously in focus on the detector.

Disclosed is an overlay measurement apparatus which may include: a light source unit configured to direct an illumination to an overlay measurement target formed in a wafer; a lens unit having an objective lens and a lens focus actuator; a detection unit acquiring a focus image at a measurement position; a stage on which the wafer is seated; and a control unit controlling the lens unit to acquire the overlay measurement target, processing a first sample image of the overlay measurement target detected by the detection unit and a second sample image rotated at 180 degrees based on the first sample image and detected, and calculating a difference between the processed images to calculate the difference as a correction image for correcting an image for which overlay is measured.