Abstract: A method of measuring a parameter of a patterning process, the method including obtaining a measurement of a substrate processed by a patterning process, with a first metrology target measurement recipe; obtaining a measurement of the substrate with a second, different metrology target measurement recipe, wherein measurements using the first and second metrology target measurement recipes have their own distinct sensitivity to a metrology target structural asymmetry of the patterning process; and determining a value of the parameter by a weighted combination of the measurements of the substrate using the first and second metrology target measurement recipes, wherein the weighting reduces or eliminates the effect of the metrology target structural geometric asymmetry on the parameter of the patterning process determined from the measurements using the first and second metrology target measurement recipes.

Abstract: A method includes exposing number of fields on a substrate, obtaining data about a field and correcting exposure of the field in subsequent exposures. The method includes defining one or more sub-fields of the field based on the obtained data. Data relating to each sub-field is processed to produce sub-field correction information. A subsequent exposure of the one or more sub-fields is corrected using the sub-field correction information. By controlling a lithographic apparatus by reference to data of a particular sub-field within a field, overlay error can be reduced or minimized for a critical feature, rather than being averaged over the whole field. By controlling a lithographic apparatus with reference to a sub-field rather than only the whole field, a residual error can be reduced in each sub-field.

Abstract: A method is proposed involving obtaining data regarding an expected focus offset during a patterning process due to topography of a region of a substrate surface. A modification of, e.g., a transmission or reflection of a region of a patterning device associated with the region of the substrate surface is determined based on the data. Using the patterning device modified according the determined modification during the patterning process mitigates an impact of the substrate topography on a parameter of the patterning process.

Abstract: A technique to generate predicted data for control or monitoring of a production process to improve a parameter of interest. Context data associated with operation of the production process is obtained. Metrology/testing is performed on the product of the production process, thereby obtaining performance data. A context-to-performance model is provided to generate predicted performance data based on labeling of the context data with performance data. This is an instance of semi-supervised learning. The context-to-performance model may include the learner that performs semi-supervised labeling. The context-to-performance model is modified using prediction information related to quality of the context data and/or performance data. Prediction information may include relevance information relating to relevance of the obtained context data and/or obtained performance data to the parameter of interest.

Abstract: A method of measuring a parameter of a patterning process, the method including obtaining a measurement of a substrate processed by a patterning process, with a first metrology target measurement recipe; obtaining a measurement of the substrate with a second, different metrology target measurement recipe, wherein measurements using the first and second metrology target measurement recipes have their own distinct sensitivity to a metrology target structural asymmetry of the patterning process; and determining a value of the parameter by a weighted combination of the measurements of the substrate using the first and second metrology target measurement recipes, wherein the weighting reduces or eliminates the effect of the metrology target structural geometric asymmetry on the parameter of the patterning process determined from the measurements using the first and second metrology target measurement recipes.

Abstract: In a lithographic process in which a series of substrates are processed in different contexts, object data (such as performance data representing overlay measured on a set of substrates that have been processed previously) is received. Context data represents one or more parameters of the lithographic process that vary between substrates within the set. By principal component analysis or other statistical analysis of the performance data, the set of substrates are partitioned into two or more subsets. The first partitioning of the substrates and the context data are used to identify one or more relevant context parameters, being parameters of the lithographic process that are observed to correlate most strongly with the first partitioning. The lithographic apparatus is controlled for new substrates by reference to the identified relevant context parameters. Embodiments with feedback control and feedforward control are described.

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 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 comprises: 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: Methods and apparatuses for determining in-plane distortion (IPD) across a substrate having a plurality of patterned regions. A method includes obtaining intra-region data indicative of a local stress distribution across one of the plurality of patterned regions; determining, based on the intra-region data, inter-region data indicative of a global stress distribution across the substrate; and determining, based on the inter-region data, the IPD across the substrate.

Abstract: Methods and apparatuses for determining a position of an alignment mark applied to a region of a first layer on a substrate using a lithographic process by: obtaining an expected position of the alignment mark; obtaining a geometrical deformation of the region due to a control action correcting the lithographic process; obtaining a translation of the alignment mark due to the geometrical deformation; and determining the position of the alignment mark based on the expected position and the translation.

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 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: 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 is proposed involving obtaining data regarding an expected focus offset during a patterning process due to topography of a region of a substrate surface. A modification of, e.g., a transmission or reflection of a region of a patterning device associated with the region of the substrate surface is determined based on the data. Using the patterning device modified according the determined modification during the patterning process mitigates an impact of the substrate topography on a parameter of the patterning process.

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: 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 including: determining first error information based on a first measurement and/or simulation result pertaining to a first patterning device in a patterning system; determining second error information based on a second measurement and/or simulation result pertaining to a second patterning device in the patterning system; determining a difference between the first error information and the second error information; and creating modification information for the first patterning device and/or the second patterning device based on the difference between the first error information and the second error information, wherein the difference between the first error information and the second error information is reduced to within a certain range after the first patterning device and/or the second patterning device is modified according to the modification information.

Abstract: Methods and associated apparatus for reconstructing a free-form geometry of a substrate, the method including: positioning the substrate on a substrate holder configured to retain the substrate under a retaining force that deforms the substrate from its free-form geometry; measuring a height map of the deformed substrate; and reconstructing the free-form geometry of the deformed substrate based on an expected deformation of the substrate by the retaining force and the measured height map.

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.