Abstract: A diffraction measurement target that has at least a first sub-target and at least a second sub-target, and wherein (1) the first and second sub-targets each include a pair of periodic structures and the first sub-target has a different design than the second sub-target, the different design including the first sub-target periodic structures having a different pitch, feature width, space width, and/or segmentation than the second sub-target periodic structure or (2) the first and second sub-targets respectively include a first and second periodic structure in a first layer, and a third periodic structure is located at least partly underneath the first periodic structure in a second layer under the first layer and there being no periodic structure underneath the second periodic structure in the second layer, and a fourth periodic structure is located at least partly underneath the second periodic structure in a third layer under the second layer.

Abstract: A method of characterizing a deformation of a plurality of substrates is described. The method includes: measuring, for a plurality of n different alignment measurement parameters ? and for a plurality of substrates, a position of the alignment marks; determining a positional deviation as the difference between the n alignment mark position measurements and a nominal alignment mark position; grouping the positional deviations into data sets; determining an average data set; subtracting the average data set from the data sets to obtain a plurality of variable data sets; performing a blind source separation method on the variable data sets, thereby decomposing the variable data sets into a set of eigenwafers representing principal components of the variable data sets; and subdividing the set of eigenwafers into a set of mark deformation eigenwafers and a set of substrate deformation eigenwafers.

Abstract: A method of determining a pellicle compensation correction which compensates for a distortion of a patterning device resultant from mounting of a pellicle onto the patterning device. The method includes determining a pellicle induced distortion from a first shape associated with the patterning device without the pellicle mounted and a second shape associated with the patterning device with the pellicle mounted, the pellicle induced distortion describing the distortion of the patterning device due to the pellicle being mounted. The determined pellicle induced distortion is then used to calculate the pellicle compensation correction for a lithographic exposure step using the patterning device.

Abstract: A method to change an etch parameter of a substrate etching process, the method including: making a first measurement of a first metric associated with a structure on a substrate before being etched; making a second measurement of a second metric associated with a structure on a substrate after being etched; and changing the etch parameter based on a difference between the first measurement and the second measurement.

Abstract: In a lithographic process, product units such as semiconductor wafers are subjected to lithographic patterning operations and chemical and physical processing operations. Alignment data or other measurements are made at stages during the performance of the process to obtain object data representing positional deviation or other parameters measured at points spatially distributed across each unit. This object data is used to obtain diagnostic information by performing a multivariate analysis to decompose a set of vectors representing the units in the multidimensional space into one or more component vectors. Diagnostic information about the industrial process is extracted using the component vectors. The performance of the industrial process for subsequent product units can be controlled based on the extracted diagnostic information.

Abstract: A diffraction measurement target that has at least a first sub-target and at least a second sub-target, and wherein (1) the first and second sub-targets each include a pair of periodic structures and the first sub-target has a different design than the second sub-target, the different design including the first sub-target periodic structures having a different pitch, feature width, space width, and/or segmentation than the second sub-target periodic structure or (2) the first and second sub-targets respectively include a first and second periodic structure in a first layer, and a third periodic structure is located at least partly underneath the first periodic structure in a second layer under the first layer and there being no periodic structure underneath the second periodic structure in the second layer, and a fourth periodic structure is located at least partly underneath the second periodic structure in a third layer under the second layer.

Abstract: A method of determining an optimal operational parameter setting of a metrology system is described. Free-form substrate shape measurements are performed. A model is applied, transforming the measured warp to modeled warp scaling values. Substrates are clamped to a chuck, causing substrate deformation. Alignment marks of the substrates are measured using an alignment system with four alignment measurement colors. Scaling values thus obtained are corrected with the modeled warp scaling values to determine corrected scaling values. An optimal alignment measurement color is determined, based on the corrected scaling values. Optionally, scaling values are selected that were measured using the optimal alignment measurement color and a substrate grid is determined using the selected scaling values. A substrate may be exposed using the determined substrate grid to correct exposure of the substrate.

Abstract: Methods, systems, and apparatus for reducing electrical arcing in a connector. The connector includes a pin contact having a pin tip end and a pin base end, the pin contact at the pin base end being made of a first material having a first resistance and the plug contact at the tip end being made of a second material having a second resistance greater than the first resistance. The connector also includes a socket contact configured to receive the pin contact, and the socket contact configured to establish an electrical connection with the pin contact to transfer electrical power, the second material of the pin contact configured to prevent electrical arcing by suppressing electrical voltage when the pin contact is mated or unmated from the socket contact while electrical power is being transferred.

Abstract: A method of devising a target arrangement, and associated target and reticle. The target includes a plurality of gratings, each grating having a plurality of substructures. The method includes: defining a target area; locating the substructures within the target area so as to form the gratings; and locating assist features at the periphery of the gratings, the assist features being configured to reduce measured intensity peaks at the periphery of the gratings. The method may include an optimization process including modelling a resultant image obtained by inspection of the target using a metrology process; and evaluating whether the target arrangement is optimized for detection using a metrology process.

Abstract: A method to form on a substrate a first target comprising a first feature and a second target comprising a second feature, wherein the forming of the targets comprises applying the first feature and the second feature to the substrate by projection of a radiation beam through a production patterning device installed in a lithographic apparatus, the features corresponding to one or more features of the patterning device, and controlling a configuration of the lithographic apparatus to induce an aberration component, such that the first feature is applied to the substrate using a first value of an induced aberration component and the second feature is applied to the substrate using a second, different value of the induced aberration component; measuring a property of the targets; and using the measurements to determine a sensitivity of the property of the targets to changes in value of the induced aberration component.

Abstract: In a lithographic process, product units such as semiconductor wafers are subjected to lithographic patterning operations and chemical and physical processing operations. Alignment data or other measurements are made at stages during the performance of the process to obtain object data representing positional deviation or other parameters measured at points spatially distributed across each unit. This object data is used to obtain diagnostic information by performing a multivariate analysis to decompose a set of vectors representing the units in said multidimensional space into one or more component vectors. Diagnostic information about the industrial process is extracted using the component vectors. The performance of the industrial process for subsequent product units can be controlled based on the extracted diagnostic information.

Abstract: A patterning device cooling system for thermally conditioning a patterning device of a lithographic apparatus, wherein the patterning device in use, is being irradiated by exposure radiation, wherein the patterning device cooling system has: a thermal conditioner configured to thermally condition the patterning device; and a controller configured to control the thermal conditioner to thermally condition the patterning device dependent on an amount of the exposure radiation absorbed by the patterning device.

Abstract: A lithographic process includes clamping a substrate onto a substrate support, measuring positions across the clamped substrate, and applying a pattern to the clamped substrate using the positions measured. A correction is applied to the positioning of the applied pattern in localized regions of the substrate, based on recognition of a warp-induced characteristic in the positions measured across the substrate. The correction may be generated by inferring one or more shape characteristics of the warped substrate using the measured positions and other information. Based on the one or more inferred shape characteristics, a clamping model is applied to simulate deformation of the warped substrate in response to clamping. A correction is calculated based on the simulated deformation.

Abstract: A method for determining a mechanical property of a layer applied to a substrate and associated control system for controlling a lithographic process. The method includes obtaining measured out-of-plane deformation of the substrate, the out-of-plane deformation including deformation normal to a substrate plane defined by, or parallel to, a substrate surface. The measured out-of-plane deformation is fitted to a second order polynomial in two coordinates associated with the substrate plane and the mechanical property (e.g. anisotropic Young's moduli) of the layer is determined based on characteristics of the fitted second order polynomial. The mechanical property of the layer can be used to calibrate an in-plane distortion model of the substrate for predicting in-plane distortion based on the measured out-of-plane deformation.

Abstract: The invention relates to a dichroic prism assembly (P1-P7) configured to receive light from an object image through an entrance face of the dichroic prism assembly, comprising a first prism (P3) and a further dichroic prism assembly (P5, P6, P7) for splitting light in three light components, the first prism having a cross section with at least five corners, each corner having an inside angle of at least 90 degrees. The corners of the first prism are designed so that an incoming beam which enters the entrance face in a direction parallel to a normal of said entrance face is reflected twice inside the prism and exits the prism through an exit face parallel to a normal of said exit face, wherein the normal of the entrance face and the normal of the exit face are perpendicular to each other, and wherein the dichroic prism assembly comprises a compensator prism (P4) between the first prism and the further dichroic prism assembly.

Abstract: A substrate has a plurality of overlay gratings formed thereon by a lithographic process. Each overlay grating has a known overlay bias. The values of overlay bias include for example two values in a region centered on zero and two values in a region centered on P/2, where P is the pitch of the gratings. Overlay is calculated from asymmetry measurements for the gratings using knowledge of the different overlay bias values, each of the overall asymmetry measurements being weighted by a corresponding weight factor. Each one of the weight factors represents a measure of feature asymmetry within the respective overlay grating. The calculation is used to improve subsequent performance of the measurement process, and/or the lithographic process. Some of the asymmetry measurements may additionally be weighted by a second weight factor in order to eliminate or reduce the contribution of phase asymmetry to the overlay.

Abstract: A method including modeling high resolution patterning error information of a patterning process involving a patterning device in a patterning system using an error mathematical model, modeling a correction of the patterning error that can be made by a patterning device modification tool using a correction mathematical model, the correction mathematical model having substantially the same resolution as the error mathematical model, and determining modification information for modifying the patterning device using the patterning device modification tool by applying the correction mathematical model to the patterning error information modeled by the error mathematical model.

Abstract: A method including: obtaining information regarding a patterning error in a patterning process involving a patterning device; determining a nonlinearity over a period of time introduced by modifying the patterning error by a modification apparatus according to the patterning error information; and determining a patterning error offset for use with the modification apparatus based on the determined nonlinearity.

Abstract: A method including obtaining a measurement and/or simulation result of a pattern after being processed by an etch tool of a patterning system, determining a patterning error due to an etch loading effect based on the measurement and/or simulation result, and creating, by a computer system, modification information for modifying a patterning device and/or for adjusting a modification apparatus upstream in the patterning system from the etch tool based on the patterning error, wherein the patterning error is converted to a correctable error and/or reduced to a certain range, when the patterning device is modified according to the modification information and/or the modification apparatus is adjusted according to the modification information.

Abstract: A method including identifying that an area of a first substrate includes a hotspot based on a measurement and/or simulation result pertaining to a patterning device in a patterning system, determining first error information at the hotspot, and creating first modification information for modifying the patterning device (e.g., the information to be transmitted with the patterning device to a patterning modification tool) based on the first error information to obtain a modified patterning device.