Abstract: Methods and inspection apparatus and computer program products for assessing a quality of reconstruction of a value of a parameter of interest of a structure, which may be applied for example in metrology of microscopic structures. It is important the reconstruction provides a value of a parameter of interest (e.g. a CD) of the structure which is accurate as the reconstructed value is used to monitor and/or control a lithographic process. This is a way of assessing a quality of reconstruction (803) of a value of a parameter of interest of a structure which does not require the use of a scanning electron microscope, by predicting (804) values of the parameter of interest of structures using reconstructed values of parameters of structures, and by comparing (805) the predicted values of the parameter of interest and the reconstructed values of the parameter of interest.

Abstract: A method of configuring a parameter determination process, the method including: obtaining a mathematical model of a structure, the mathematical model configured to predict an optical response when illuminating the structure with a radiation beam and the structure having geometric symmetry at a nominal physical configuration; using, by a hardware computer system, the mathematical model to simulate a perturbation in the physical configuration of the structure of a certain amount to determine a corresponding change of the optical response in each of a plurality of pixels to obtain a plurality of pixel sensitivities; and based on the pixel sensitivities, determining a plurality of weights for combination with measured pixel optical characteristic values of the structure on a substrate to yield a value of a parameter associated with change in the physical configuration, each weight corresponding to a pixel.

Abstract: A method of determining overlay of a patterning process, the method including: illuminating a substrate with a radiation beam such that a beam spot on the substrate is filled with one or more physical instances of a unit cell, the unit cell having geometric symmetry at a nominal value of overlay; detecting primarily zeroth order radiation redirected by the one or more physical instances of the unit cell using a detector; and determining, by a hardware computer system, a non-nominal value of overlay of the unit cell from values of an optical characteristic of the detected radiation.

Abstract: A method of determining a parameter of a patterning process, the method including: obtaining a detected representation of radiation redirected by a structure having geometric symmetry at a nominal physical configuration, wherein the detected representation of the radiation was obtained by illuminating a substrate with a radiation beam such that a beam spot on the substrate was filled with the structure; and determining, by a hardware computer system, a value of the patterning process parameter based on optical characteristic values from an asymmetric optical characteristic distribution portion of the detected radiation representation with higher weight than another portion of the detected radiation representation, the asymmetric optical characteristic distribution arising from a different physical configuration of the structure than the nominal physical configuration.

Abstract: A metrology target includes: a first structure arranged to be created by a first patterning process; and a second structure arranged to be created by a second patterning process, wherein the first structure and/or second structure is not used to create a functional aspect of a device pattern, and wherein the first and second structures together form one or more instances of a unit cell, the unit cell having geometric symmetry at a nominal physical configuration and wherein the unit cell has a feature that causes, at a different physical configuration than the nominal physical configuration due to a relative shift in pattern placement in the first patterning process, the second patterning process and/or another patterning process, an asymmetry in the unit cell.

Abstract: A method of determining overlay of a patterning process, the method including: obtaining a detected representation of radiation redirected by one or more physical instances of a unit cell, wherein the unit cell has geometric symmetry at a nominal value of overlay and wherein the detected representation of the radiation was obtained by illuminating a substrate with a radiation beam such that a beam spot on the substrate was filled with the one or more physical instances of the unit cell; and determining, from optical characteristic values from the detected radiation representation, a value of a first overlay for the unit cell separately from a second overlay for the unit cell that is also obtainable from the same optical characteristic values, wherein the first overlay is in a different direction than the second overlay or between a different combination of parts of the unit cell than the second overlay.

Abstract: A method including determining one or more statistical features from data obtained from a lithography process, a lithography apparatus, a substrate processed by the lithography process or the lithography apparatus, wherein determining the one or more statistical features does not include reconstructing a characteristic of the lithography process, of the lithography apparatus, or of the substrate.

Abstract: A method including obtaining measurement results of a device manufacturing process or a product thereof, obtaining sets of one or more values of one or more parameters of a distribution by fitting the distribution against the measurement results, respectively, and obtaining, using a computer, a set of one or more values of one or more hyperparameters of a hyperdistribution by fitting the hyperdistribution against the sets of values of the parameters.

Abstract: A substrate has first and second target structures formed thereon by a lithographic process. Each target structure has two-dimensional periodic structure formed in a single material layer on a substrate using first and second lithographic steps, wherein, in the first target structure, features defined in the second lithographic step are displaced relative to features defined in the first lithographic step by a first bias amount that is close to one half of a spatial period of the features formed in the first lithographic step, and, in the second target structure, features defined in the second lithographic step are displaced relative to features defined in the first lithographic step by a second bias amount close to one half of said spatial period and different to the first bias amount.

Abstract: A method of determining edge placement error within a structure produced using a lithographic process, the method comprising the steps of: (a) receiving a substrate comprising a first structure produced using the lithographic process, the first structure comprising first and second layers, each of the layers having first areas of electrically conducting material and second areas of non-electrically conducting material; (b) receiving a target signal indicative of a first target relative position which is indicative of a target position of edges between the first areas and the second areas of the first layer relative to edges between the first areas and second areas of the second layer in the first structure during said lithographic process; (c) detecting scattered radiation while illuminating the first structure with optical radiation to obtain a first signal; and (d) ascertaining an edge placement error parameter on the basis of the first signal and the first target relative position.

Abstract: In order to determine whether an exposure apparatus is outputting the correct dose of radiation and its projection system is focusing the radiation correctly, a test pattern is used on a mask for printing a specific marker onto a substrate. This marker is then measured by an inspection apparatus, such as a scatterometer, to determine whether there are errors in focus and dose and other related properties. The test pattern is configured such that changes in focus and dose may be easily determined by measuring the properties of a pattern that is exposed using the mask. The test pattern may be a 2D pattern where physical or geometric properties, e.g., pitch, are different in each of the two dimensions. The test pattern may also be a one-dimensional pattern made up of an array of structures in one dimension, the structures being made up of at least one substructure, the substructures reacting differently to focus and dose and giving rise to an exposed pattern from which focus and dose may be determined.

Abstract: Methods and inspection apparatus and computer program products for assessing a quality of reconstruction of a value of a parameter of interest of a structure, which may be applied for example in metrology of microscopic structures. It is important the reconstruction provides a value of a parameter of interest (e.g. a CD) of the structure which is accurate as the reconstructed value is used to monitor and/or control a lithographic process. This is a way of assessing a quality of reconstruction (803) of a value of a parameter of interest of a structure which does not require the use of a scanning electron microscope, by predicting (804) values of the parameter of interest of structures using reconstructed values of parameters of structures, and by comparing (805) the predicted values of the parameter of interest and the reconstructed values of the parameter of interest.

Abstract: A method of determining a critical-dimension-related property, such as critical dimension (CD) or exposure dose, includes illuminating each of a plurality of periodic targets having different respective critical dimension biases, measuring intensity of radiation scattered by the targets, recognizing and extracting each grating from the image, determining a differential signal, and determining the CD-related property based on the differential signal, the CD biases and knowledge that the differential signal approximates to zero at a 1:1 line-to-space ratio of such periodic targets. Use of the determined CD-related property to control a lithography apparatus in lithographic processing of subsequent substrates. In order to use just two CD biases, a calibration may use measurements on a “golden wafer” (i.e. a reference substrate) to determine the intensity gradient for each of the CD pairs, with known CDs. Alternatively, the calibration can be based upon simulation of the sensitivity of intensity gradient to CD.

Abstract: A method of determining exposure dose of a lithographic apparatus used in a lithographic process on a substrate, the method comprising the steps: (a) receiving a substrate comprising first and second structures produced using the lithographic process; (b) detecting scattered radiation while illuminating the first structure with radiation to obtain a first scatterometer signal; (c) detecting scattered radiation while illuminating the second structure with radiation to obtain a second scatterometer signal; (d) using the first and second scatterometer signals to determine an exposure dose value used to produce said first and second structures wherein the first structure has a first periodic characteristic with spatial characteristics and yet at least another second periodic characteristic with spatial characteristics designed to be affected by the exposure dose and the second structure has a first periodic characteristic with spatial characteristics and yet at least another second periodic characteristic with sp

Abstract: Disclosed are methods, apparatuses, and lithographic systems for calibrating an inspection apparatus. Radiation is projected onto a pattern in a target position of a substrate. By making a plurality of measurements of the pattern and comparing the measured first or higher diffraction orders of radiation reflected from the pattern of different measurements, a residual error indicative of the error in a scatterometer may be calculated. This error is an error in measurements of substrate parameters caused by irregularities of the scatterometer. The residual error may manifest itself as an asymmetry in the diffraction spectra.

Abstract: In order to determine whether an exposure apparatus is outputting the correct dose of radiation and a projection system of the exposure apparatus is focusing the radiation correctly, a test pattern is used on a mask for printing a specific marker onto a substrate. This marker may be measured by an inspection apparatus, such as, for example, a scatterometer to determine whether errors in focus, dose, and other related properties are present. The test pattern is arranged such that changes in focus and dose may be easily determined by measuring properties of a pattern that is exposed using the mask. The test pattern of the mask is arranged so that it gives rise to a marker pattern on the substrate surface. The marker pattern contains structures that have at least two measurable side wall angles. Asymmetry between side wall angles of a structure is related to focus (or defocus) of the exposure radiation from the exposure apparatus.

Abstract: An orthopedic device for compressing or distracting bone parts includes an elongated body with two arms extending transversely away from the body. One arm is a stationary arm affixed to one end of the body and a second arm is a longitudinally movable. The two arms extend from the elongated body in the same direction and parallel to each other. The orthopedic device also includes a locking sleeve hingeably connected to the outer end of each of the first and second arms by a hinge joint, where each locking sleeve is configured for lockably receiving an elongated pin using a collet and a captured collet nut.

Abstract: A method of determining exposure dose of a lithographic apparatus used in a lithographic process on a substrate. Using the lithographic process to produce a first structure on the substrate, the first structure having a dose-sensitive feature which has a form that depends on exposure dose of the lithographic apparatus on the substrate. Using the lithographic process to produce a second structure on the substrate, the second structure having a dose-sensitive feature which has a form that depends on the exposure dose of the lithographic apparatus but which has a different sensitivity to the exposure dose than the first structure. Detecting scattered radiation while illuminating the first and second structures with radiation to obtain first and second scatterometer signals. Using the first and second scatterometer signals to determine an exposure dose value used to produce at least one of the first and second structures.

Abstract: For angular resolved spectrometry a radiation beam is used having an illumination profile having four quadrants is used. The first and third quadrants are illuminated whereas the second and fourth quadrants aren't illuminated. The resulting pupil plane is thus also divided into four quadrants with only the zeroth order diffraction pattern appearing in the first and third quadrants and only the first order diffraction pattern appearing in the second and third quadrants.

Abstract: In a method of determining the focus of a lithographic apparatus used in a lithographic process on a substrate, the lithographic process is used to form a structure on the substrate, the structure having at least one feature which has an asymmetry in the printed profile which varies as a function of the focus of the lithographic apparatus on the substrate. A first image of the periodic structure is formed and detected while illuminating the structure with a first beam of radiation. The first image is formed using a first part of non-zero order diffracted radiation. A second image of the periodic structure is formed and detected while illuminating the structure with a second beam of radiation. The second image is formed using a second part of the non-zero order diffracted radiation which is symmetrically opposite to the first part in a diffraction spectrum.