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.

The system includes a radiation source, a diffractive element, an optical system, a detector, and a processor. The radiation source generates radiation. The diffractive element diffracts the radiation to generate a first beam and a second beam. The first beam includes a first non-zero diffraction order and the second beam includes a second non-zero diffraction order that is different from the first non-zero diffraction order. The optical system receives a first scattered beam and a second scattered radiation beam from a target structure and directs the first scattered beam and the second scattered beam towards a detector. The detector generates a detection signal. The processor analyzes the detection signal to determine a target structure property based on at least the detection signal. The first beam is attenuated with respect to the second beam or the first scattered beam is purposely attenuated with respect to the second scattered beam.

An illumination apparatus configured to provide illumination while changing a spectrum of light from a light source includes a wavelength variable unit configured to change a spectrum of irradiating light, and an optical system configured to irradiate the wavelength variable unit with the light from the light source. The wavelength variable unit is disposed so that an incident surface of the wavelength variable unit on which the light emitted from the optical system is incident is tilted with respect to a plane perpendicular to an optical axis of the optical system.

A method of detecting coordinates of a mark is provided. The method includes: providing a plurality of structures and the mark on a wafer, each of the plurality of structures including a plurality of mold insulating layers and a plurality of mold sacrificial layers, which are alternately stacked, an end of each of the plurality of structures including a portion having a stair shape, and the mark being between adjacent structures among the plurality of structures; forming a photoresist layer on the plurality of structures and the mark, the photoresist layer including a portion concave toward the wafer between the adjacent structures; detecting the coordinates of the mark by irradiating a beam to the mark; determining an offset of the coordinates of the mark based on a beam path changing factor; and correcting the coordinates of the mark based on the offset.

An exposure apparatus exposes an object to pattern light generated by a spatial light modulator having a plurality of elements in accordance with drawing data. The exposure apparatus includes a data output unit configured to output the drawing data to the spatial light modulator, an illumination optical system configured to irradiate the spatial light modulator with illumination light, a first movable body configured to hold the object, a projection optical system configured to project an image of the pattern light generated by the spatial light modulator onto the object, a detection unit configured to detect the image of the pattern light that has been projected, and a determination unit configured to determine whether the spatial light modulator is capable of generating pattern light in accordance with the drawing data output from the data output unit, based on a detection result of the detection unit.

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.

An image based overlay measuring method may include an overlay mark preparation step, an overlay signal generation step and an overlay measuring step. The overlay mark preparation step may include preparing an image based overlay mark including a lower pattern and an upper pattern. The lower pattern and the upper pattern may have an overlapped portion from a planar view. The overlay signal generation step may include generating a lower overlay signal from a lower non-overlapped region of the lower pattern and an upper overlay signal from an upper non-overlapped region of the upper pattern using image information of the image based overlay mark. The overlay measuring step may include comparing the lower overlay signal with the upper overlay signal to measure an overlay.

A measurement system is presented configured for integration with a processing equipment for applying optical measurements to a structure. The measurement system comprises: a support assembly for holding a structure under measurements in a measurement plane, configured and operable for rotation in a plane parallel to the measurement plane and for movement along a first lateral axis in said measurement plane; an optical system defining illumination and collection light channels of normal and oblique optical schemes and comprising an optical head comprising at least three lens units located in the illumination and collection channels; a holder assembly comprising: a support unit for carrying the optical head, and a guiding unit for guiding a sliding movement of the support unit along a path extending along a second lateral axis perpendicular to said first lateral axis; and an optical window arrangement comprising at least three optical windows made in a faceplate located between the optical head at a certain distance from the measurement plane. The optical windows are aligned with the illumination and collection channels for, respectively, propagation of illuminating light from the optical head and propagation of light returned from an illuminated region to the optical head, in accordance with the normal and oblique optical schemes.

An assembly and method for separating first radiation and second radiation in the far field, wherein the first radiation and the second radiation have non-overlapping wavelengths, The assembly comprises a capillary structure, wherein the first radiation and the second radiation propagate coaxially along at least a portion of the capillary structure, and an optical structure configured to control the spatial distribution of the first radiation outside of the capillary structure, through interference, such that the intensity of the first radiation in the far field is reduced along an optical axis of the second radiation.