Abstract: A metrology target includes a first target structure formed within at least one of a first area and a third area of a first layer of a sample, where the first target structure comprises a plurality of first cells containing one or more first cell pattern elements; and a second target structure formed within at least one of a second area and a fourth area of a second layer of the sample, the second target structure comprising a plurality of second cells containing one or more second cell pattern elements.

Abstract: 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.

Abstract: A product includes at least one semiconductor substrate, multiple thin-film layers disposed on the at least one substrate, and an overlay target formed in at least one of the thin-film layers. The overlay target includes a first sub-target having a first center of symmetry and including first target features having a first linewidth, and a second sub-target having a second center of symmetry coincident with the first center of symmetry and including second target features, which have a second linewidth, greater than the first linewidth, and are adjacent to but non-overlapping with the first target features.

Abstract: A light detection and ranging (LIDAR) controller is disclosed. The LIDAR controller may determine, based on a position of an implement, a scan area of the LIDAR sensor, wherein the scan area has an increased point density relative to another area of a field of view, of the LIDAR sensor, that includes the implement. The LIDAR controller may cause the LIDAR sensor to capture, with the increased point density, LIDAR data associated with the scan area. The LIDAR controller may process the LIDAR data to determine whether an object of interest is in an environment of the machine that is associated with the scan area. The LIDAR controller may perform an action based on the environment of the machine.

Abstract: A method for calibrating a scanning charged particle microscope, such as a scanning electron microscope (SEM), is provided. The method includes dividing a wafer into a plurality of regions; preparing, on each of the plurality of regions, a pattern including a first periodic structure interleaved with a second periodic structure, the first and second periodic structures having an induced offset; determining an actual pitch the first and second periodic structures and thereby determining actual induced offset on each of the plurality of regions; selecting a plurality of regions from among the plurality of regions; measuring, by the SEM, a pitch of first and second periodic structures on each of the plurality of regions; and performing linearity calibration on the SEM based on the determining and the measuring.

Abstract: Display device includes a flexible substrate, a plurality of pixels disposed on a first surface of flexible substrate, and a plurality of alignment marks disposed along one side of the flexible substrate and identified each other. The plurality of alignment marks may be arranged in the same layer. When the plurality of pixels includes thin film transistor, the plurality of alignment marks may be formed of the same metal layer as the metal layer forming thin film transistor.

Abstract: A misregistration measurement and region of interest selection system (MMRSS) for measuring misregistration between at least two layers on a wafer in the manufacture of semiconductor devices, the MMRSS including a set of misregistration metrology tools, including at least two misregistration metrology tools, and a misregistration analysis and region of interest selection engine operative to: analyze a plurality of misregistration measurement data sets associated with a set of regions of interest (ROIs) of at least one measurement site on the wafer and at least partially generated by at least one first misregistration metrology tool, and wherein each of the data sets is associated with a set of quality metrics, identify a recommended ROI and communicate the recommended ROI to at least one second misregistration metrology tool of the set of misregistration metrology tools, the second misregistration metrology tool being operative to generate misregistration metrology data associated with the recommended ROI.

Abstract: A method for metrology includes directing at least one illumination beam to illuminate a semiconductor wafer on which at least first and second patterned layers have been deposited in succession, including a first target feature in the first patterned layer and a second target feature in the second patterned layer, overlaid on the first target feature. A sequence of images of the first and second target features is captured while varying one or more imaging parameters over the sequence. The images in the sequence are processed in order to identify respective centers of symmetry of the first and second target features in the images and measure variations in the centers of symmetry as a function of the varying image parameters. The measured variations are applied in measuring an overlay error between the first and second patterned layers.

Abstract: Disclosed is a method for detecting a shadow in an image of an eye region of a user wearing a Head Mounted Device, HMD. The method comprises obtaining, from a camera of the HMD, an image of the eye region of the user wearing a HMD and determining an area of interest in the image, the area of interest comprising a plurality of subareas. The method further comprises determining a first brightness level for a first subarea of the plurality of subareas and determining a second brightness level for a second subarea of the plurality of subareas. The method further comprises comparing the first brightness level with the second brightness level, and, based on the comparing, selectively generating a signal indicating a shadow.

Abstract: A photomask for negative-tone development (NTD) includes a main region, and a scribe lane region surrounding the main region and including a first lane and a second lane. The first and the second lane is provided at first opposite sides of each other with respect to the main region. The first lane includes a first sub-lane extending in a first direction and a second sub-lane that extending in the first direction. The first sub-lane includes a first dummy pattern and the second sub-lane includes a second dummy pattern. The first dummy pattern and the second dummy pattern are configured to radiate light exceeding a threshold dose of light to a first portion of a negative-tone photoresist provided under the first lane of the photomask.

Abstract: A method for monitoring a lithographic process, and associated lithographic apparatus. The method includes obtaining height variation data relating to a substrate supported by a substrate support and fitting a regression through the height variation data, the regression approximating the shape of the substrate; residual data between the height variation data and the regression is determined; and variation of the residual data is monitored over time. The residual data may be deconvolved based on known features of the substrate support.

Abstract: A method of determining a position of a feature (for example an alignment mark) on an object (for example a silicon wafer) is disclosed. The method comprises determining an offset parameter, determining the second position; and determining a first position from the second position and the offset parameter, the position of the mark being the first position. The offset parameter is a measure of a difference in: a first position that is indicative of the position of the feature; and a second position that is indicative of the position of the feature. The offset parameter may be determined using a first measurement apparatus and the second position may be determined using a second, different measurement apparatus.

Abstract: Embodiments disclosed herein include a method of determining the position of a sensor wafer relative to a pedestal. In an embodiment, the method comprises placing a sensor wafer onto the pedestal, wherein the sensor wafer comprises a first surface that is supported by the pedestal, a second surface opposite the first surface, and an edge surface connecting the first surface to the second surface, wherein a plurality of sensor regions are formed on the edge surface, and wherein the pedestal comprises a major surface and an annular wall surrounding the sensor wafer. In an embodiment, the method further comprises determining a gap distance between each of the plurality of sensor regions and the annular wall. In an embodiment, the method may further comprise determining a center-point offset of a center-point of the sensor wafer relative to a center point of the annular wall from the gap distances.

Abstract: A metrology target is disclosed, in accordance with one or more embodiments of the present disclosure. The metrology target includes a first set of pattern elements having a first pitch, where the first set of pattern elements includes segmented pattern elements. The metrology target includes a second set of pattern elements having a second pitch, where the second set of pattern elements includes segmented pattern elements. The metrology target includes a third set of pattern elements having a third pitch, where the third set of pattern elements includes segmented pattern elements.

Abstract: Provided is a position measurement apparatus in which a measurement error in a target is reduced. A position measurement apparatus measuring a position of a target includes an illumination unit configured to illuminate the target with illumination light including light of a first wavelength and light of a second wavelength different from the first wavelength, a measurement unit configured to measure the position of the target by detecting light from the target illuminated with the illumination light, and a control unit configured to adjust a ratio of a light intensity of the first wavelength to a light intensity of the second wavelength such that a measurement error varying depending on the position of the target in the measurement unit is reduced.

Abstract: An image-based overlay metrology system is disclosed. The system includes a controller couplable to a metrology sub-system. The controller is configured to receive a set of image signals of a first metrology target disposed on the sample from the metrology sub-system and determine a plurality of harmonic detectivity metric values by calculating a harmonic detectivity metric value for each of the plurality of image signals. The controller is also configured to identify a set of optical measurement conditions of the metrology sub-system based on the plurality of harmonic detectivity metric values, wherein the set of optical measurement conditions define a recipe for optical metrology measurements of the metrology sub-system. The controller then provides the recipe to the metrology sub-system for execution of one or more optical metrology measurements of one or more additional metrology targets.

Abstract: A scatterometer for measuring a property of a target on a substrate includes a radiation source, a detector, and a processor. The radiation source produces a radiated spot on the target. The scatterometer adjusts a position of the radiated spot along a first direction across the target and along a second direction that is at an angle with respect to the first direction. The detector receives radiation scattered by the target. The received radiation is associated with positions of the radiated spot on the target along at least the first direction. The detector generates measurement signals based on the positions of the radiated spot on the target. The processor outputs, based on the measurement signals, a single value that is representative of the property of the target. The processor also combines the measurement signals to output a combined signal and derives, based on the combined signal, the single value.

Abstract: An overlay metrology system may include, an illumination sub-system, a collection sub-system and a controller. The illumination sub-system may include one or more illumination optics configured to direct an illumination beam to an overlay target on a sample as the sample is scanned along a stage-scan direction by a translation stage, where the overlay target includes one or more cells having a grating-over-grating structure with periodicity along the stage-scan direction. The collection sub-system may include an objective lens, a first photodetector located in a pupil plane at a location of overlap between 0-order diffraction and +1-order diffraction, and a second photodetector located in a pupil plane at a location of overlap between 0-order diffraction and ?1-order diffraction. The controller may receive time-varying interference signals from the first and second photodetectors and determine an overlay error between the first and second layers of the sample along the stage-scan direction.

Abstract: Metrology methods and tools are provided, which enhance the accuracy of the measurements and enable simplification of the measurement process as well as improving the correspondence between the metrology targets and the semiconductor devices. Methods comprise illuminating the target in a Littrow configuration to yield a first measurement signal comprising a ?1st diffraction order and a 0th diffraction order and a second measurement signal comprising a +1st distraction order and a 0th diffraction order, wherein the ?1st diffraction order of the first measurement signal and the +1st diffraction order of the second measurement signal are diffracted at 180° to a direction of the illumination, performing a first measurement of the first measurement signal and a second measurement of the second measurement signal, and deriving metrology metric(s) therefrom. Optionally, a reflected 0th diffraction order may be split to yield components which interact with the ?1st and +1st diffraction orders.

Abstract: A position detection apparatus configured to detect a pattern including a plurality of pattern elements formed on an object includes a control unit configured to detect the pattern by performing pattern matching between a template including a plurality of feature points and the plurality of pattern elements. While, performing pattern matching, the control unit changes positions of the plurality of feature points such that a correlation between an image and the template is within a predetermined allowable range.

Abstract: A back alignment mark on a surface of a semiconductor substrate is detected and a resist mask patterned into a circuit pattern corresponding to a surface element structure is formed on a back of the semiconductor substrate. Detection of the back alignment mark is performed by using a detector opposing the back of the semiconductor substrate and measuring contrast based on the intensity of reflected infrared light irradiated from the back of the semiconductor substrate. The back alignment mark is configured by a step formed by the surface of the semiconductor substrate and bottoms of trenches formed from the surface of the semiconductor substrate. A polysilicon film is embedded in the trenches. The back alignment mark has, for example, a cross-shaped planar layout in which three or more trenches are disposed in a direction parallel to the surface of the semiconductor substrate.

Abstract: An acquiring unit of a structured illuminating microscopy apparatus acquires at least two modulated images having the same wave number vector and the different phases; and a calculating unit of the structured illuminating microscopy apparatus, in a spatial frequency spectrum of each of at least the two modulated images acquired by the acquiring unit, separates a 0th-order modulating component and ±first-order modulating components of observational light fluxes superimposed on arbitrary two observation points based on at least four observation values regarding the two observation points which are mutually displaced by an amount of the wave number vector.

Abstract: The present invention provides a method for performing high dynamic range low inter-pixel spatial and wavelength crosstalk optical image detection in a camera comprising an Optical Array Device (OAD), a point Photo Detector (PD) and a Photo Detector Array (PDA) sensor. The method comprises imaging incident light from an object onto an image plane of the Optical Array Device (OAD) to form an incident image map; selecting by the OAD and the Point Photo Detector and by the OAD and the Photo Detector Array a plurality of pixels on the incident image map for time-frequency coding; time-frequency coding the selected pixels by the OAD; detecting by the point PD the optical irradiance values of the time-frequency coded pixels output from the OAD; and performing signal processing on the detected optical irradiance values to determine the light intensity of each of the selected pixels.

Abstract: Method of measuring a height profile of one or more substrates is provided comprising measuring a first height profile of one or more fields on a substrate using a first sensor arrangement, the first height profile being the sum of a first interfield part and a first intrafield part, measuring a second height profile of one or more further fields on the substrate or on a further substrate using a second sensor arrangement, the second height profile being the sum of a second interfield part and a second intrafield part, determining from the measurements with the first sensor arrangement an average first intrafield part, and determining the height profile of the further fields from the second interfield part and the average first intrafield part thereby correcting the measurements of the second sensor arrangement.

Abstract: A printing device is provided comprising a camera to capture an image of at least a portion of a print substrate; a controller to determine a location of a portion of a side edge of the substrate from the image to determine a distance of the print substrate from a predetermined location; and adjustment apparatus to adjust the entire substrate laterally, relative to the direction of transport of the substrate, based on the determined location.

Abstract: Methods, apparatuses, and systems related to determining overlay of features of a memory array are described. An example method includes forming a plurality of contacts on a working surface and selectively forming a first portion of a layer of conductive lines and a second portion of the layer of conductive lines in contact with the contacts. The first portion of the layer of conductive lines formed over the working surface is separated from the second portion of the layer of conductive lines formed over the working surface by a gap. The method includes determining an overlay of at least one of the contacts formed over the working surface in the gap relative to one of the conductive lines formed over the working surface.

Abstract: A display device including: a substrate having display area and a non-display area; and an alignment mark disposed in the non-display area of the substrate. The alignment mark includes a quadrangular-shaped center portion and a plurality of measurement portions that surround the center portion, the plurality of measurement portions including four or more measurement portions, and each of the measurement portions including sides that are parallel with two sides of the quadrangular-shaped center portion.

Abstract: Methods and systems for positioning a specimen and characterizing an x-ray beam incident onto the specimen in a Transmission, Small-Angle X-ray Scatterometry (T-SAXS) metrology system are described herein. A specimen positioning system locates a wafer vertically and actively positions the wafer in six degrees of freedom with respect to the x-ray illumination beam without attenuating the transmitted radiation. In some embodiments, a cylindrically shaped occlusion element is scanned across the illumination beam while the detected intensity of the transmitted flux is measured to precisely locate the beam center. In some other embodiments, a periodic calibration target is employed to precisely locate the beam center. The periodic calibration target includes one or more spatially defined zones having different periodic structures that diffract X-ray illumination light into distinct, measurable diffraction patterns.

Abstract: Metrology targets, design files, and design and production methods thereof are provided. The targets comprise two or more parallel periodic structures at respective layers, wherein a predetermined offset is introduced between the periodic structures, for example, opposite offsets at different parts of a target. Quality metrics are designed to estimate the unintentional overlay from measurements of a same metrology parameter by two or more alternative measurement algorithms. Target parameters are configured to enable both imaging and scatterometry measurements and enhance the metrology measurements by the use of both methods on the same targets. Imaging and scatterometry target parts may share elements or have common element dimensions. Imaging and scatterometry target parts may be combined into a single target area or may be integrated into a hybrid target using a specified geometric arrangement.

Abstract: An imprint apparatus performs an imprint process by bringing a mold into contact with an imprint material arranged on a shot region of a substrate and curing the imprint material. The apparatus includes a controller configured to execute, in a case where an elapsed time from the supplying of the imprint material to the shot region until the contact with the mold falls outside an allowable range of a predetermined elapsed time, adjustment processing of adjusting an amount of the imprint material on the shot region at the timing of the contact.

Abstract: Disclosed is an inspection apparatus for use in lithography. It comprises a support for a substrate carrying a plurality of metrology targets; an optical system for illuminating the targets under predetermined illumination conditions and for detecting predetermined portions of radiation diffracted by the targets under the illumination conditions; a processor arranged to calculate from said detected portions of diffracted radiation a measurement of asymmetry for a specific target; and a controller for causing the optical system and processor to measure asymmetry in at least two of said targets which have different known components of positional offset between structures and smaller sub-structures within a layer on the substrate and calculate from the results of said asymmetry measurements a measurement of a performance parameter of the lithographic process for structures of said smaller size. Also disclosed are substrates provided with a plurality of novel metrology targets formed by a lithographic process.

Abstract: An electronic device includes a stack assembly and a cover glass. The stack assembly includes an electrophoretic display sub-assembly for rendering content, a front light sub-assembly comprising a light guide, a light FPC, and a plurality of light sources, and a capacitive touch sensing sub-assembly for detecting touch inputs. A yellow-pigmented tape is applied over the light sources and an edge of the light guide. A stiffener member is coupled to the light FPC opposite the yellow-pigmented tape.

Abstract: Provided are an apparatus and a method for measuring a three dimensional shape with improved accuracy. The apparatus includes a stage, at least one lighting unit, a plurality of image pickup units and a control unit. The stage supports an object to be measured. The lighting unit includes a light source and a grid, and radiates grid-patterned light to the object to be measured. The image pickup units capture, in different directions, grid images reflected from the object to be measured. The control unit calculates a three dimensional shape of the object from the grid images captured by the image pickup units. The present invention has advantages in capturing grid images through a main image pickup portion and sub-image pickup portions, enabling the measurement of the three dimensional shape of the object in a rapid and accurate manner.

Abstract: A method of measuring overlay uses a plurality of asymmetry measurements from locations (LOI) on a pair of sub-targets (1032, 1034) formed on a substrate (W). For each sub-target, the plurality of asymmetry measurements are fitted to at least one expected relationship (1502, 1504) between asymmetry and overlay, based on a known bias variation deigned into the sub-targets. Continuous bias variation in one example is provided by varying the pitch of top and bottom gratings (P1/P2). Bias variations between the sub-targets of the pair are equal and opposite (P2/P1). Overlay (OV) is calculated based on a relative shift (xs) between the fitted relationships for the two sub-targets. The step of fitting asymmetry measurements to at least one expected relationship includes wholly or partially discounting measurements (1506, 1508, 1510) that deviate from the expected relationship and/or fall outside a particular segment of the fitted relationship.

Abstract: An orientation system includes a base station comprising a light emitter that projects a pattern onto a projection surface of a space, an auxiliary station including an auxiliary emitter that projects an auxiliary pattern onto the projection surface, and a robot including a moveable base supporting an imaging device. The robot detects the pattern and the auxiliary pattern with the imaging device, and determines a location of the robot within the space based on the pattern.

Abstract: A method of assembling a group of devices, the method comprising the steps of: evacuating a space between each component of a first group of two or more components on a source device and a transfer device thereby to create a temporary bond between each component of the first group of two or more components and the transfer device; selectively removing the first group of two or more components from the source device whilst the transfer device is temporarily bonded to each component of the first group of two or more components on the source device; positioning the first group of two or more components on a host device; and decoupling the first group of two or more components from the transfer device, thereby to form a first group of assembled devices.

Abstract: Methods, systems and devices for automatically focusing a microscope on a specimen and collecting a focused image of the specimen are provided. Aspects of the methods include detecting the presence of a substrate in a microscope, determining whether the substrate is in a correct orientation for imaging, focusing the microscope on a specimen that is placed on the substrate, and collecting one or more images of the specimen. Systems and devices for carrying out the subject methods are also provided.

Abstract: Novel instructions, their format, and support thereof are described. For example, an instruction including a field for an opcode to indicate a reduction-based mask generation operation is to be performed, a field to identify a first packed data source operand, a field to identify a second packed data source operand, and a field to identify a destination operand to store reduction-based generated mask and its hardware support is described.

Abstract: Position data may gradually pseudonymized by a method, comprising: generating a sequence of relative positions from a sequence of absolute positions of a moving object; randomizing the sequence of relative positions using at least a sequence of random numbers generated from at least one seed; in response to receiving an analytical job comprising the at least one seed, restoring the sequence of relative positions from the randomized sequence of relative positions; and in response to receiving an analytical job comprising both the at least one seed and at least one absolute position derived from the sequence of absolute positions, restoring the sequence of absolute positions from the randomized sequence of relative positions.

Abstract: Disclosed are mask definition tools, apparatus, methods, systems and computer program products configured to process data representing a semiconductor fabrication mask. A non-limiting example of a method includes performing a decomposition process on a full Transmission Cross Coefficient (TCC) using coherent optimal coherent systems (OCS) kernels; isolating a residual TCC that remains after some number of coherent kernels are extracted from the full TCC; and performing at least one decomposition process on the residual TCC using at least one loxicoherent system. The loxicoherent system uses a plurality of distinct non-coherent kernel functions and is a compound system containing a paired coherent system and an incoherent system that act in sequence. An output of the coherent system is input as a self-luminous quantity to the incoherent system, and the output of the incoherent system is an output of the loxicoherent system.

Abstract: Focusing methods and modules are provided for metrology tools and systems. Methods comprise capturing image(s) of at least two layers of a ROI in an imaging target, binning the captured image(s), deriving a focus shift from the binned captured image(s) by comparing the layers, and calculating a focus position from the derived focus shift. Disclosed methods are direct, may be carried out in parallel to a part of the overlay measurement process and provide fast and simple focus measurements that improve metrology performance.

Abstract: A metrology apparatus for determining a characteristic of interest of a structure on a substrate, the apparatus comprising: a radiation source for generating illumination radiation; at least two illumination branches for illuminating the structure on the substrate, the illumination branches being configured to illuminate the structure 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: In order to provide an optical sensor that is capable of obtaining both an optical trap effect and a moth eye effect with a single texture structure, a semiconductor optical sensor according to the present invention includes a light absorption medium that has a refractive index n and a thickness sufficiently less than a light transmission length, wherein the center wavelength to be observed is defined as ?. The semiconductor optical sensor is characterized by: having, in a light incident surface, a texture structure having a random surface direction and a typical structure scale d defined as in (?/n).

Abstract: A position detection device for adjusting positions of a mold and a substrate using a mold mark formed on the mold and a substrate mark formed on the substrate includes a detection unit configured to detect light from the mold mark and the substrate mark, and a processing unit configured to obtain a positional relationship between the substrate and the mold based on a detection result of the detection unit, wherein the processing unit obtains the positional relationship between the substrate and the mold based on a corrected signal obtained by removing a noise component based on the light from the mold mark from a detected signal based on the light from the mold mark and the substrate mark.

Abstract: Scatterometry overlay (SCOL) single cell targets are provided, along with target design methods and measurement methods which employ the single cell SCOL targets for in-die metrology measurements, utilizing the small size of the target along with maintained optical performance due to the design of the target. Disclosed single cell targets comprise a lattice of elements at two or more layers which is periodic two or more measurement directions. Elements in different layers are offset with respect to each other and may have the same pitch along the measurement directions. Measurement algorithms are also provided to derive metrology measurements such as overlays from the single cell targets, possibly simultaneously in both (or more) measurement directions, reducing measurement time and enhancing the metrology throughput. Positioning the small targets in-die provides more accurate metrology results which are less sensitive to process variation.

Abstract: A method for determining the position of an optical boundary surface along a first direction includes a) imaging a pattern in a plane transverse to the first direction, and recording a two-dimensional image of the pattern imaged in the plane; b) repeating step a) for different positions in the first direction, wherein the different positions cover an area in the first direction in which the optical boundary surface lies; c) averaging each image from step a) along a direction transverse to the second direction such that in each case a one-dimensional data set is produced; d) transforming each data set from step c) into a frequency domain; e) determining the frequency of the greatest amplitude of all data sets transformed in step d); and f) determining the position along the first direction by evaluating the data sets transformed in step d) at the frequency determined in step e).

Abstract: A light detection device includes a diffraction element and a light detection element. The diffraction element diffracts a beam of light that is incident on the diffraction element. The light detection element includes light receivers to receive diffracted light. The diffraction element generates beams of the diffracted light by dividing the beam of light. The light detection element determines a displacement of the beam of light relative to the diffraction element on the basis of quantities of light of the beams of the diffracted light. The light detection element determines an angle change of the beam of light relative to the diffraction element by dividing the quantity of light of one of the beams of the diffracted light.

Abstract: A method for measuring overlay at a semiconductor device on which circuit patterns are formed by a plurality of exposure processes is characterized in including an image capturing step for capturing images of a plurality of areas of the semiconductor device, a reference image setting step for setting a reference image based on a plurality of the images captured in the image capturing step, a difference quantifying step for quantifying a difference between the reference image set in the reference image setting step and the plurality of images captured in the image capturing step, and an overlay calculating step for calculating the overlay based on the difference quantified in the difference quantifying step.

Abstract: A photonic integrated circulator can be fabricated by including a plurality of polarizing beam splitters and optical polarization rotators such that two copies of the optical signal are output at a receiver in substantially aligned polarization states. The circulator can be used for facilitating bi-directional communications between photonic integrated circuit devices, which are inherently polarization sensitive, while reducing signal loss.

Abstract: A detection device includes an illumination optical system and a detection optical system. The illumination optical system is configured to illuminate a first diffraction grating having a first period in a first direction and a second diffraction grating having a second period different from the first period. The detection optical system is configured to detect light diffracted by the first and second diffraction gratings. The illumination optical system includes an optical member configured to form, on a pupil plane, a first pole and a second pole opposite to the first pole. The illumination optical system causes lights from the first and second poles to obliquely enter the first and second diffraction gratings from the first direction to illuminate the first and second diffraction gratings. The detection optical system detects diffracted light diffracted by one of the first and second diffraction gratings and by an other diffraction grating.