Abstract: A metrology tool for determining a parameter of interest of a structure fabricated on a substrate, the metrology tool comprising: an illumination optical system for illuminating the structure with illumination radiation under a non-zero angle of incidence; a detection optical system comprising a detection optical sensor and at least one lens for capturing a portion of illumination radiation scattered by the structure and transmitting the captured radiation towards the detection optical sensor, wherein the illumination optical system and the detection optical system do not share an optical element.

Abstract: A sensor is disclosed, wherein a transducer generates acoustic waves, which are received by a lens assembly. The lens assembly transmits and directs at least a part of the acoustic waves to a target. The lens assembly then receives at least a part of acoustic waves, after interaction with the target. The sensor further comprises an optical detector that comprises at least one optically reflective member located at a surface of the lens assembly, which surface is arranged opposite to a surface of the lens assembly which faces a focal plane of the lens assembly, wherein the at least one optically reflective member is mechanically displaced in response to the acoustic waves, which are received and transmitted by the lens assembly.

Abstract: A micromirror array comprises a substrate, a plurality of mirrors for reflecting incident light and, for each mirror of the plurality of mirrors, at least one multilayer piezoelectric actuator for displacing the mirror, wherein the at least one multilayer piezoelectric actuator is connected to the substrate, and wherein the at least one multilayer piezoelectric actuator comprises a plurality of piezoelectric layers of piezoelectric material interleaved with a plurality of electrode layers to form a stack of layers. Also disclosed is a method of forming such a micromirror array. The micromirror array may be used in a programmable illuminator. The programmable illuminator may be used in a lithographic apparatus and/or in an inspection and/or metrology apparatus.

Abstract: A micromirror array comprises a substrate, a plurality of mirrors for reflecting incident light and, for each mirror of the plurality of mirrors, at least one piezoelectric actuator for displacing the mirror, wherein the at least one piezoelectric actuator is connected to the substrate. The micromirror array further comprises one or more pillars connecting the mirror to the at least one piezoelectric actuator. Also disclosed is a method of forming such a micromirror array. The micromirror array may be used in a programmable illuminator. The programmable illuminator may be used in a lithographic apparatus and/or in an inspection and/or metrology apparatus.

Abstract: 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.

Abstract: A dark field digital holographic microscope and associated metrology method is disclosed which is configured to determine a characteristic of interest of a structure. The dark field digital holographic microscope includes an illumination branch for providing illumination radiation to illuminate the structure; a detection arrangement for capturing object radiation resulting from diffraction of the illumination radiation by the structure; and a reference branch for providing reference radiation for interfering with the object radiation to obtain an image of an interference pattern formed by the illumination radiation and reference radiation. The reference branch has an optical element operable to vary a characteristic of the reference radiation so as to reduce and/or minimize variation in a contrast metric of the image within a field of view of the dark field digital holographic microscope at a detector plane.

Abstract: Disclosed is a detection apparatus for a metrology device operable to measure a parameter of interest from scattered radiation having been scattered from a sample. The detection device comprises a detector comprising an array of pixels. The array of pixels comprises imaging pixels for detecting an image from which the parameter of interest is determined, and direction detecting pixels for detecting the angle of incidence of said scattered radiation on said detector.

Abstract: A metrology apparatus for determining a parameter of interest of a structure formed by a lithographic process on a substrate, the metrology apparatus comprising: an illuminator for illuminating the structure; a lens for collecting at least a portion of radiation diffracted from the structure; and an image sensor for receiving and obtaining a recording of the collected diffracted radiation; wherein the illuminator comprises at least one optical fiber for illuminating the structure directly.

Abstract: Described is a metrology system for determining a characteristic of interest relating to at least one structure on a substrate, and associated method. The metrology system comprises a processor being configured to computationally determine phase and amplitude information from a detected characteristic of scattered radiation having been reflected or scattered by the at least one structure as a result of illumination of said at least one structure with illumination radiation in a measurement acquisition, and use the determined phase and amplitude to determine the characteristic of interest.

Abstract: A dark field digital holographic microscope is disclosed which is configured to determine a characteristic of interest of a structure. The dark field digital holographic microscope comprises an illumination device configured to provide at least: a first beam pair comprising a first illumination beam of radiation (1010) and a first reference beam of radiation (1030) and a second beam pair comprising a second illumination beam of radiation (1020) and a second reference beam of radiation (1040); and one or more optical elements (1070) operable to capture a first scattered radiation and to capture a second scattered radiation scattered by the structure resultant from the first and second illumination beams respectively. The beams of the first beam pair are mutually coherent and the beams of the second beam pair are mutually coherent. The illumination device is configured to impose incoherence (ADI) between the first beam pair and second beam pair.

Abstract: A metrology apparatus for determining a characteristic of interest of a structure on a substrate, the apparatus comprising: a radiation source configured to generate illumination radiation; at least two illumination branches comprising at least one optical fiber and configured to illuminate a structure on a substrate from different angles; and a radiation switch configured to receive the illumination radiation and transfer at least part of the radiation to a selectable one of the at least two illumination branches.

Abstract: An acoustic scatterometer has an acoustic source operable to project acoustic radiation onto a periodic structure and formed on a substrate. An acoustic detector is operable to detect the ?1st acoustic diffraction order diffracted by the periodic structure and while discriminating from specular reflection (0th order). Another acoustic detector is operable to detect the +1st acoustic diffraction order diffracted by the periodic structure, again while discriminating from the specular reflection (0th order). The acoustic source and acoustic detector may be piezo transducers. The angle of incidence of the projected acoustic radiation and location of the detectors and are arranged with respect to the periodic structure and such that the detection of the ?1st and +1st acoustic diffraction orders and discriminates from the 0th order specular reflection.

Abstract: A micromirror array includes a substrate, a plurality of mirrors for reflecting incident radiation, and for each mirror of the plurality of mirrors, a respective post connecting the substrate to the respective mirror. The micromirror array further includes, for each mirror of the plurality of mirrors, one or more electrostatic actuators connected to the substrate for applying force to the respective post to displace the respective post relative to the substrate, thereby displacing the respective mirror. Also disclosed is a method of forming such a micromirror array. The micromirror array may be used in a programmable illuminator. The programmable illuminator may be used in a lithographic apparatus and/or in an inspection apparatus.

Abstract: Disclosed is a detection apparatus for a metrology device operable to measure a parameter of interest from scattered radiation having been scattered from a sample. The detection device comprises a detector comprising an array of pixels. The array of pixels comprises imaging pixels for detecting an image from which the parameter of interest is determined, and direction detecting pixels for detecting the angle of incidence of said scattered radiation on said detector.

Abstract: Disclosed is a method and associated inspection apparatus for measuring a characteristic of interest relating to a structure on a substrate. The inspection apparatus uses measurement radiation comprising a plurality of wavelengths. The method comprises performing a plurality of measurement acquisitions of said structure, each measurement acquisition being performed using measurement radiation comprising a different subset of the plurality of wavelengths, to obtain a plurality of multiplexed measurement signals. The plurality of multiplexed measurement signals are subsequently de-multiplexed into signal components according to each of said plurality of wavelengths, to obtain a plurality of de-multiplexed measurement signals which are separated according to wavelength.

Abstract: Disclosed is a method of determining a complex-valued field relating to a sample measured using an imaging system. The method comprises obtaining image data relating to a series of images of the sample, imaged at an image plane of the imaging system, and for which at least two different modulation functions are imposed in a Fourier plane of the imaging system; and determining the complex-valued field from the imaging data based on the imposed modulation functions.

Abstract: Disclosed is a method of measuring a structure, and associated metrology device and computer program. The method comprises obtaining an amplitude profile of scattered radiation relating to a measurement of a first structure on a first substrate and obtaining a reference phase profile relating to a reference measurement of at least one reference structure on a reference substrate. The at least one reference structure is not the same structure as said first structure but is nominally identical in terms of at least a plurality of key parameters. The method further comprises determining a complex-valued field to describe the first structure from the amplitude profile and reference phase profile.

Abstract: A micromirror array comprises a substrate, a plurality of minors for reflecting incident light and, for each mirror (20) of the plurality of minors, at least one piezoelectric actuator (21) for displacing the minor, wherein the at least one piezoelectric actuator is connected to the substrate. The micromirror array further comprises one or more pillars (24) connecting the minor to the at least one piezoelectric actuator. Also disclosed is a method of forming such a micromirror array. The micromirror array may be used in a programmable illuminator. The programmable illuminator may be used in a lithographic apparatus and/or in an inspection apparatus.

Abstract: An illumination and detection apparatus for a metrology tool, and associated method. The apparatus includes an illumination arrangement operable to produce measurement illumination having a plurality of discrete wavelength bands and having a spectrum having no more than a single peak within each wavelength band. The detection arrangement includes a detection beamsplitter to split scattered radiation into a plurality of channels, each channel corresponding to a different one of the wavelength bands; and at least one detector for separate detection of each channel.

Abstract: Described is a metrology system for determining a characteristic of interest relating to at least one structure on a substrate, and associated method. The metrology system comprises a processor being configured to computationally determine phase and amplitude information from a detected characteristic of scattered radiation having been reflected or scattered by the at least one structure as a result of illumination of said at least one structure with illumination radiation in a measurement acquisition, and use the determined phase and amplitude to determine the characteristic of interest.