Abstract: Apparatus for the detection of print marks with a sensor arrangement which has at least one contrast sensor, which for generation of a cyclical sensor signal is disposed above the area of printed material containing the print mark which is passed below the contrast sensor, said apparatus also having a signal conditioning unit. The signal conditioning unit has at least one filter unit with a first filter for determination of the first derivation of the sensor signal, and on the basis of an evaluation of at least the first derivation of the sensor signal the filter unit generates at least one output value which is representative of print marks.

Abstract: A method of aligning a diffractive optical system, to be operated with an operating beam, comprises: aligning (558) the diffractive optical system using an alignment beam having a different wavelength range from the operating beam and using a diffractive optical element optimized (552) to diffract the alignment beam and the operating beam in the same (or a predetermined) direction. In an example, the alignment beam comprises infra-red (IR) radiation and the operating beam comprises soft X-ray (SXR) radiation. The diffractive optical element is optimized by providing it with a first periodic structure with a first pitch (pIR) and a second periodic structure with a second pitch (pSXR). After alignment, the vacuum system is pumped down (562) and in operation the SXR operating beam is generated (564) by a high harmonic generation (HHG) optical source pumped by the IR alignment beam’ optical source.

Abstract: A method for positioning a mobile device relative to a stationary device in a semiconductor manufacturing environment is disclosed. The method includes detecting a target affixed to the stationary device at a target location, wherein the target location corresponds to a location of the target relative to a reference point on the stationary device, determining a first position coordinate offset value based upon detecting the target, and moving the mobile device, using the first position coordinate offset value, relative to train the mobile device to move relative to the stationary device for the stationary device to performing a semiconductor manufacturing operation.

Abstract: There are provided a welding monitoring system which can multidimensionally monitor a welding portion with high accuracy and a monitoring method thereof, by using a relatively simple configuration.

Abstract: Combination of a stage and a level sensor configured to sense a height level at a target location on an object is described, the stage comprising an object table configured to hold the object and a positioning device for displacing the object table relative to the level sensor in a first direction, the level sensor comprising a projection system configured to project a measurement beam onto a measurement area of the object, the measurement area having a measurement area length in the first direction, a detector system configured to receive different portions of the measurement beam after being reflected off different sub-areas within the measurement area, the different sub-areas being arranged in the first direction, and to supply output signals representative of the different portions received, a signal processing system configured to process the output signals from the detector system.

Abstract: An optical measurement device and method are disclosed. A position measurement device is provided with a device for measuring inclinations of an optical detection module (5) and a substrate carrier (6) which are measured during movement of the optical detection unit and the substrate carrier. Calculation and correction can be made according to the inclination data and with reference to displacements of the optical detection module (5) and the substrate carrier (6) and coordinates of their positions. During measurement for a certain point on the substrate, measured data related to the point is corrected by using the device and the method, which improves measurement precision, thus eliminating a large error caused in measurement for a large-sized substrate (9).

Abstract: A lithographic apparatus prints a focus metrology pattern (T) on a substrate, the printed pattern including at least a first array of features (800). Features at any location within the array define a pattern that repeats at in at least a first direction of periodicity (X), while geometric parameters of the repeating pattern (w1, w3) vary over the array. A focus measurement is derived from measurements of the array at a selected subset of locations (ROI). As a result, the geometric parameters upon which the measurement of focus performance is based can be optimized by selection of locations within the array. The need to optimize geometric parameters of a target design on a reticle (MA) is reduced or eliminated. The measured property may be asymmetry, for example, and/or diffraction efficiency. The measured property for all locations may be captured by dark-field imaging, and a subset of locations selected after capture.

Abstract: An imprint apparatus includes a mold holder for holding a mold, a substrate holder for holding a substrate, a dispenser for arranging imprint material on the substrate, and a scope for capturing an image of a mark. The substrate holder includes a reference plate having a reference mark whose image is captured by the scope, the dispenser is arranged in a first direction when viewed from the mold holder, and the reference plate is arranged between a virtual straight line which is parallel to a second direction perpendicular to the first direction when viewed from the mold holder and passes through a center of the substrate holder, and an edge of the substrate holder located in the first direction when viewed from the virtual straight line.

Abstract: Provided is an inclination measuring device with excellent convenience. An inclination measuring device includes: an optical system (sensor head) configured to irradiate a measurement object with an irradiated light ray from a light source and receive a reflected light ray from a measurement surface; a light receiving unit including at least one spectroscope configured to separate the reflected light ray into wavelength components, and a detector in which a plurality of light receiving elements are disposed; a light guide including a plurality of cores; and a processor configured to calculate an inclination angle of the measurement surface based on reflected light rays with respect to a plurality of irradiated light rays with which a plurality of positions on the measurement surface are irradiated.

Abstract: The present invention provides a pattern forming apparatus including a detection optical system configured to obtain optical information of a mark provided on a substrate by detecting the mark, and a processing unit configured to perform a process of obtaining a position of the mark by using a template for obtaining the position of the mark by being applied to the optical information of the mark and a window which indicates a region for extracting an amount of characteristic indicating the position of the mark from a waveform signal obtained from the optical information, wherein the processing unit decides, based on the optical information of the mark obtained by the detection optical system, a parameter indicating at least one of a shape of the template and a shape of the window for each of a plurality of substrates.

Abstract: A method includes receiving a wafer, defining a plurality of zones over the wafer, performing a multi-zone alignment compensation for each of the plurality of zones according to an equation along a first direction to obtain a plurality of compensation values for each of the plurality of zones, and performing a wafer alignment and a lithography exposure for each of the plurality of zones according to the plurality of compensation values. The wafer alignment and the lithography exposure are performed zone-by-zone.

Abstract: In some examples, a method for nondestructive testing of a component may include flashing the component using a flash lamp configured for flash thermography, collecting first image data regarding the component using an infrared camera, flowing a fluid through the component, and collecting second image data regarding the component using the infrared camera. A system for nondestructive testing of a component may include a single inspection station and a flash lamp configured for flash thermography, means for supplying a fluid to the component, and an infrared camera disposed at the inspection station.

Abstract: Provided is an electronic device having a control device, a driver circuit coupled to the control device. The driver circuit is configured to alter conductance. A partial power source is coupled to the control device and is configured to provide a voltage potential difference to the control device and the driver circuit as a result of the partial power source being in contact with a conductive fluid. The partial power source includes a first material electrically coupled to the control device and a second material electrically coupled to the control device and electrically isolated from the first material. An inductor is coupled to the driver circuit. The driver circuit is configured to develop a current through the inductor. The magnitude of the current developed through the inductor is varied to produce an encoded signal that is remotely detectable by a receiver. Receivers to receive and decode also are disclosed.

Abstract: Metrology overlay targets are provided, as well as method of monitoring process shortcomings. Targets comprise periodic structures, at least one of which comprising repeating asymmetric elements along a corresponding segmentation direction of the periodic structure. The asymmetry of the elements may be designed in different ways, for example as repeating asymmetric sub-elements along a direction perpendicular to the segmentation direction of the elements. The asymmetry of the sub-elements may be designed in different ways, according to the type of monitored process shortcomings, such as various types of hot spots, line edge shortening, process windows parameters and so forth. Results of the measurements may be used to improve the process and/or increase the accuracy of the metrology measurements.

Abstract: The present invention provides a lithography apparatus that forms patterns on substrates including a first substrate and a second substrate following the first substrate, the apparatus including a decision unit configured to obtain a first layout of a plurality of shot regions on a first substrate from detection values of marks in sample shot regions included in each of a plurality of different combinations each constituted by at least two sample shot regions, of sample shot regions where a detection unit has detected the marks in fine alignment with respect to the first substrate and decide sample shot regions included in one of the plurality of combinations as sample shot regions where the detection unit detects the marks in pre-alignment with respect to a second substrate based on the first layout.

Abstract: A measurement device is equipped with a surface plate, a slider which holds a substrate and which is movable relative to the surface plate, a drive system that moves the slider, a first position measurement system which measures the slider's first position information relative to the surface plate, a measurement unit having a mark detection system that detects a mark on a substrate, a second position measurement system which measures a relative second position information between the mark detection system and substrate, and a controller which obtains the first position information from the first position measurement system and second position information from the second position measurement system while controlling the slider's movement by the drive system, and obtains position information of a plurality of marks based on detection signals of the mark detection system having detected marks on the substrate, the first position information, and the second position information.

Abstract: A spectrally broadened radiation apparatus, including a laser configured to emit, through an output of the laser, radiation substantially only in the visible region of the electromagnetic spectrum, the radiation having a nominal wavelength, and an optical fiber optically coupled to the output of the laser, the optical fiber having an input to receive the radiation from the laser and having an output to provide spectrally broadened output radiation, the optical fiber configured to spectrally broaden the radiation from the laser to a spectral width of at least 0.5 nm around the nominal wavelength.

Abstract: An auxiliary exposure apparatus is for performing auxiliary exposure of applying light of a predetermined wavelength from a laser light source to a resist film on a wafer, separately from exposure processing of transferring a pattern of a mask to the resist film applied on the wafer. The auxiliary exposure apparatus includes a first total reflection mirror that reflects the light from the laser light source toward the wafer; and an imaging device including a light receiving part that receives light after reflected by the wafer.

Abstract: A polarized image acquisition apparatus includes a division type half-wave plate, located opposite to the mask substrate with respect to an objective lens and near an objective lens pupil position, to arrange P and S polarized waves of the transmitted light having passed through the objective lens to be mutually orthogonal, a Rochon prism to separate trajectories of P and S polarized waves, an imaging lens to form images of P and S polarized waves having passed through the Rochon prism at image formation positions different from each other, a mirror, in a case where one of P and S polarized waves is focused/formed at one of the different image formation positions, to reflect the other wave at the other position, a first sensor to capture an image of one of P and S polarized waves, and a second sensor to capture an image of the other wave.

Abstract: An image reading apparatus includes a roller that transports a document; a reading unit that reads an image of the document which is transported; a DC motor that drives the roller; and a control unit that controls the DC motor. The control unit is configured to stop driving of the DC motor in a case where a driving load value obtained when the DC motor is driven exceeds a threshold. A first threshold which is applied in a case of a first document and a second threshold which is applied in a case of a second document of which a basis weight is larger than a first basis weight are set, and the first threshold is less than the second threshold.

Abstract: A method comprising illuminating a patterning device (MA?) comprising a plurality of patterned regions (15a-15c) of which each patterns a measurement beam (17a-17c), projecting, with a projection system (PL), the measurement beams onto a sensor apparatus (21) comprising a plurality of detector regions (25a-25c), making a first measurement of radiation when the patterning device and the sensor apparatus are positioned in a first relative configuration, moving at least one of the patterning device and the sensor apparatus so as to change the relative configuration of the patterning device to a second relative configuration, making a second measurement of radiation when the patterning device and the sensor apparatus are positioned in the second relative configuration in which at least some of the plurality of detector regions receive a different measurement beam to the measurement beam which was received at the respective detector region in the first relative configuration and determining aberrations caused by t

Abstract: Apparatus and method for testing a sheet of brittle material comprising the steps of measuring one or more edge features of a sheet of brittle material, imparting a bend to the sheet of brittle material and producing relative motion between the sheet and the bend such that the bend traverses the sheet. A stress can be induced in the sheet as a function of the relative motion and imparted bend, wherein the induced stress corresponds to a predetermined strength value, and the measured one or more edge features can be correlated with the strength value.

Abstract: A catadioptric projection objective for images an object field onto an image field via imaging radiation. The projection objective includes at least one reflective optical component and a measuring device. The reflective optical component, during the operation of the projection objective, reflects a first part of the imaging radiation and transmits a second part of the imaging radiation. The reflected, first part of the imaging radiation at least partly contributes to the imaging of the object field. The transmitted, second part of the imaging radiation is at least partly fed to a measuring device. This allows a simultaneous exposure of the photosensitive layer at the location of the image field with the imaging radiation and monitoring of the imaging radiation with the aid of the measuring device.

Abstract: The disclosure relates to an assembly in a microlithographic projection exposure apparatus, with an optical element and at least one weight compensating device, which includes at least one magnetic circuit. A magnetic field generated by this magnetic circuit brings about a force for compensating at least partially for the force of the weight acting on the optical element. The apparatus also includes a coil arrangement with a plurality of coils. The arrangement is energizable with electrical current to generate a compensating force acting on the optical element. This compensating force compensates at least partially for a parasitic force that is exerted by the magnetic circuit when there is movement of the optical element and does not contribute to the compensation for the force of the weight acting on the optical element.

Abstract: A three-dimensional image processing apparatus and a method of controlling power of same are provided. The three-dimensional image processing apparatus may include a display, a three-dimensional image filter disposed a prescribed distance from the display to adjust optical paths of the displayed view images, a camera configured to capture an image of a user, an ambient light sensor, and a controller configured to control the view images, the three-dimensional image filter, or the camera. The controller may determine a position of the user based on the captured image and adjust a perceived three-dimensional view of the view images based on the determined position of the user. Moreover, the controller may control an operational state of the camera and the at least one process based on the determined position of the user or a detected amount of ambient light.

Abstract: A semiconductor structure is disclosed. The semiconductor structure includes a substrate having a scribe line region. A material layer is formed on the scribe line region and has a rectangular region defined therein. The rectangular region has a pair of first edges parallel with a widthwise direction of the scribe line region and a pair of second edges parallel with a lengthwise direction of the scribe line region. A pair of first alignment features is formed in the material layer along the first edges, and a pair of second alignment features is formed in the material layer along the second edges. The space between the pair of first alignment features is larger than a space between the pair of the second alignment features.

Abstract: An overlay metrology system may include a controller to generate optical tool error adjustments for a hybrid overlay target including optically-resolvable features and device-scale features by measuring a difference between an optical overlay measurement based on the optically-resolvable features and a device-scale overlay measurement based on the device-scale features, generate target-to-device adjustments for the hybrid overlay target based on positions of features within the device area, determine device-relevant overlay measurements for one or more locations in the device area based on at least one of the optical overlay measurement, the optical tool error adjustments, or the target-to-device adjustments, and provide overlay correctables for the device area to a lithography tool to modify exposure conditions for at least one subsequent exposure based on the device-relevant overlay measurements.

Abstract: A lithographic apparatus has a substrate table on which a substrate is positioned, and an alignment sensor used to measure the alignment of the substrate. In an exemplary processing method, the alignment sensor is used to perform one or more edge measurements in a first step. In a second step, one or more edge measurements are performed on the notch of the substrate. The edge measurements are then used to align the substrate in the lithographic apparatus. In a particular example, the substrate is arranged relative to the alignment sensor such that a portion of the edge surface is positioned at the focal length of the lens. When the alignment sensor detects radiation scattered by the edge surface at the focal length of the lens, the presence of the edge of the substrate is detected.

Abstract: A method and apparatus for identifying the orientation of an image in a spherical format. A spherical format is created of an image obtained by a camera, the spherical format comprising a notional sphere that has a centre corresponding to the position from which the image was obtained by the camera. A first surface represented in the image had a first orientation and was at a first distance from the camera when the image was obtained. A plurality of lines are obtained in the spherical format, each line defined by two endpoints in spherical coordinates, wherein each line intersects with at least one other line. For each of a plurality of rotational definitions of the sphere, the spherical coordinates of the endpoints are transformed into a Cartesian coordinate system relative to the rotational definition, thereby creating rotated lines, and a cumulative deviation, from a predetermined angle, is determined of angles between intersecting rotated lines.

Abstract: A light combiner (500) for use in a metrology tool includes a plurality of light sources (LED 1, LED 2, LED 3, LED 4, LED 5), a first filter (502), and a second filter (504). The first filter is designed to substantially reflect light generated from a first source of the plurality of light sources, and to substantially transmit light generated from a second source of the plurality of light sources. The second filter is designed to substantially reflect light generated from the first source and the second source of the plurality of light sources, and to substantially transmit light generated from a third source of the plurality of light sources. An angle of incidence of the light generated from the first source on a surface of the first filter is less than 30 degrees.

Abstract: A reticle purging system includes an automated pod opener, a reticle holding device, a reticle transporting device and at least one purging device. The reticle holding device has a reticle occupiable zone thereon. The reticle transporting device is assigned with a transportation path from the automated pod opener to the reticle holding device. The reticle occupiable zone is exposed to the purging device.

Abstract: A lithographic apparatus includes a projection system which includes a plurality of optical elements configured to project a beam of radiation onto a radiation sensitive substrate. The lithographic apparatus also includes a metrology frame structure which includes a part of one or more optical element measurement systems to measure the position and/or orientation of at least one of the optical elements. The plurality of optical elements, a patterning device stage, and a substrate stage are arranged such that, in a two dimensional view on the projection system, a rectangle is defined such that it envelops the plurality of optical elements, the patterning device stage, and the substrate stage. The rectangle is as small as possible. The metrology frame structure is positioned within the rectangle.

Abstract: This disclosure relates to a cell alignment device for aligning a first substrate and a second substrate of a display panel. The cell alignment device comprises: a first platform and a second platform disposed oppositely; a light emitting unit disposed on a surface of the first platform facing the second platform and configured to emit light toward the second platform; a light sensing unit disposed on a surface of the second platform facing the first platform and configured to sense a light intensity of light emitted by the light emitting unit; and a control unit configured to, when the sensed light intensity is greater than or equal to a preset light intensity, adjust a position of at least one of the first platform and the second platform until the sensed light intensity is smaller than the preset light intensity.

Abstract: The present invention relates to a method and an apparatus for measuring errors of a movable platform in multiple degrees of freedom. A light-source module disposed on a fixed platform emits light to a lens module disposed on a movable platform. The light is reflected to one or more optoelectronic sensing module on the fixed platform via the lenses of the lens module. Then a processing unit calculates an alignment error or/and one or more straightness error or/and one or more angle error of the movable platform according to the signal generated by the optoelectronic sensing module.

Abstract: A method for adjusting an inkjet printing apparatus, an inkjet printing method, an inkjet printing apparatus, and a system including the same. The inkjet printing apparatus includes a plurality of nozzles, and the method for adjusting the inkjet printing apparatus includes: obtaining images of liquid drops which are output respectively from the plurality of nozzles during an inkjet printing process after the liquid drops are dried; and adjusting a driving parameter of at least one nozzle of the plurality of nozzles based upon the images of the liquid drops which are output respectively from the plurality of nozzles after the liquid drops are dried, so that volumes of the liquid drops which are output respectively from the plurality of nozzles are substantially same.

Abstract: A focus detection device includes: a plurality of micro-lenses at which light fluxes through an image forming optical system enter, disposed in a two-dimensional array pattern; a plurality of light receiving elements disposed in correspondence to each of the plurality of micro-lenses; a focus detection unit that executes a detection of a defocus quantity of the image forming optical system by detecting, based upon outputs from the plurality of light receiving elements, a phase difference of a plurality of light fluxes through different areas of the image forming optical system; and a recognition unit that recognizes, based upon the outputs from the plurality of light receiving elements, characteristics of a subject image formed onto the plurality of light receiving elements via the plurality of micro-lenses, wherein: the focus detection unit detects the defocus quantity through a method optimal for the characteristics of the subject image recognized by the recognition unit.

Abstract: A scanner has a first mirror having a plurality of concavities configured to reflect light from a document; and a sensor configured to detect light reflected by the concavity; the concavity having an optical characteristic that differs according to position.

Abstract: Disclosed is a method, system, and apparatus for optical emission measurement. The apparatus includes a collection system for collecting a plasma optical emission spectra through an optical window disposed at a wall of a plasma processing chamber. The optical system includes a mirror configured to scan a plurality of non-coincident rays across the plasma processing chamber; and a telecentric coupler for collecting an optical signal from a plasma and directing the optical signal to a spectrometer for measuring the plasma optical emission spectra.

Abstract: A closed-loop adaptive material deposition apparatus and method uses a scanning system to monitor an additively manufactured object as it is being fabricated and adapting the geometric shape and material composition of the subsequent layers based on the scan data. The scanning system repeatedly captures geometric and/or material information of a partially manufactured object with optional auxiliary objects inserted during the manufacturing process. Based on this information, the actual surface geometry and/or actual material composition is computed. Surface geometry may be offset and used as a slicing surface for the next portion of the digital model. The shape of the slicing surface may then be recomputed each time the system scans the partially fabricated object.

Abstract: An object is to provide an illumination apparatus that achieves illumination with a uniform illuminance distribution, while reducing a light quantity loss. An illumination apparatus for illuminating an illumination target surface has: a deflection member configured to form an illuminance distribution with a periodic pattern along a predetermined direction on a predetermined face traversing an optical path; and an optical integrator system having a plurality of wavefront division facets arrayed on the predetermined face and configured to form secondary light sources with use of a beam from the deflection member; the deflection member forms the illuminance distribution with the periodic pattern of an integer times or a unit fraction times an array period of the plurality of wavefront division facets.

Abstract: According to an aspect of the invention, an exposure method includes: moving a substrate during a period from a start to an end of exposure performed on any region among a plurality of exposure regions, wherein a timing at which the substrate is moved during the period is determined on the basis of a difference between a width of the pattern formed on the substrate in a first direction on a surface of the substrate and a width of the pattern formed on the substrate in a second direction on the surface of the substrate different from the first direction.

Abstract: Ink jet printing can be used in the production of electro-optic displays for (a) forming a layer of a polymer-dispersed electrophoretic medium on a substrate; (b) forming a color electro-optic layer; (c) forming a color filter; and (d) printing electrodes and/or associated conductors on a layer of electro-optic material.

Abstract: In a display panel, multiple first alignment patterns are disposed in a non-display area on a first substrate, and each first alignment pattern includes a first portion and a second portion connected to each other. Multiple second alignment patterns are disposed in the non-display area on a second substrate, and each of the second alignment patterns includes a third portion and a fourth portion. There is a first length difference between the length of each first portion along a first direction and the length of the corresponding third portion along the first direction, and the first length differences are different from each other. There is a second length difference between the length of each second portion along a second direction and the length of the corresponding fourth portion along the second direction, and the second length differences are different from each other.

Abstract: Embodiments of the present disclosure generally relate to apparatuses and systems for performing photolithography processes. More particularly, compact apparatuses for projecting an image onto a substrate are provided. In one embodiment, an image projection apparatus includes a light pipe coupled to a first mounting plate, and a frustrated prism assembly, one or more digital micro-mirror devices, one or more beamsplitters, and one or more projection optics, which are coupled to a second mounting plate. The first and second mounting plates are coplanar, such that the image projection apparatus is compact and may be aligned in a system having a plurality of image projection apparatuses, each of which is easily removable and replaceable.

Abstract: Examination system, method and computer-readable medium, the method comprising: processing by a processor using a first recipe at least one image comprised in images and metadata generated by an inspection tool and stored, to detect a first location set of first potential defects and attributes thereof; selecting and imaging part of the first location set with a review tool to obtain an image set; obtaining classification results of said first potential defects and determining a further recipe based thereon; processing the image using the further recipe for detecting a further location set of further defects; selecting part of the further location set; imaging the part with the review tool to obtain a further image set, and obtaining further classification results; and repeating determining the further recipe, processing the image, selecting and imaging part of the further location set, and obtaining further classification results, until a stopping criteria is met.

Abstract: A lithography mask is disclosed. The lithography mask includes at least one asymmetric segmented pattern element. A particular asymmetric segmented pattern element includes at least two segments with a separation distance between consecutive segments smaller than a resolution of a set of projection optics for generating an image of the particular asymmetric segmented pattern element on a sample such that the image of the particular asymmetric segmented pattern element is an unsegmented pattern image. A position of the unsegmented pattern image on the sample is indicative of a location of the sample along an optical axis of the set of projection optics.

Abstract: A method including obtaining a measurement result from a target on a substrate, by using a substrate measurement recipe; determining, by a hardware computer system, a parameter from the measurement result, wherein the parameter characterizes dependence of the measurement result on an optical path length of the target for incident radiation used in the substrate measurement recipe and the determining the parameter includes determining dependence of the measurement result on a relative change of wavelength of the incident radiation; and if the parameter is not within a specified range, adjusting the substrate measurement recipe.

Abstract: A system including a controller, an interface, and a calibration controller. The controller is configured to (i) select a set of fields, and (ii) based on the set of fields, supply control effort to first actuators in zones of a chamber. The interface is configured to receive feedback signals from sensors. The feedback signals are indicative of fields respectively of the zones. The controller is configured to adjust an amount of control effort supplied to the actuators based on the fields. The calibration controller is configured to, based on the fields, generate calibration values for each of the sensors. The calibration values for each of the sensors are indicative of field contributions corresponding respectively to the actuators.

Abstract: Systems and methods for improving results of wafer higher order shape (HOS) characterization and wafer classification are disclosed. The systems and methods in accordance with the present disclosure are based on localized shapes. A wafer map is partitioned into a plurality of measurement sites to improve the completeness of wafer shape representation. Various site based HOS metric values may be calculated for wafer characterization and/or classification purposes, and may also be utilized as control input for a downstream application. In addition, polar grid partitioning schemes are provided. Such polar grid partitioning schemes may be utilized to partition a wafer surface into measurement sites having uniform site areas while providing good wafer edge region coverage.

Abstract: Disclosed are a method, computer program and associated apparatuses for metrology. The method includes acquiring inspection data comprising a plurality of inspection data elements, each inspection data element having been obtained by inspection of a corresponding target structure formed using a lithographic process; and performing an unsupervised cluster analysis on said inspection data, thereby partitioning said inspection data into a plurality of clusters in accordance with a metric. In an embodiment, a cluster representative can be identified for each cluster. The cluster representative may be reconstructed and the reconstruction used to approximate the other members of the cluster.