Abstract: Disclosed is a method for determining a focus parameter value used to expose at least one structure on a substrate. The method comprises obtaining measurement data relating to a measurement of said at least one structure, wherein the at least one structure comprises a single periodic structure per measurement location and decomposing said measurement data into component data comprising one or more components of said measurement data. At least one of said components is processed to extract processed component data having a reduced dependence on non-focus related effects and a value for the focus parameter is determined from said processed component data. Associated apparatuses and patterning devices are also disclosed.

Abstract: A method of determining a patterning process parameter from a metrology target, the method including: obtaining a plurality of values of diffraction radiation from the metrology target, each value of the plurality of values corresponding to a different illumination condition of a plurality of illumination conditions of illumination radiation for the target; and using the combination of values to determine a same value of the patterning process parameter for the target.

Abstract: Disclosed is a method comprising measuring radiation reflected from a metrology target and decomposing the measured radiation in components, for example Fourier components or spatial components. Further, there is disclosed a recipe selection method which provides an algorithm to select a parameter of the metrology apparatus based on re-calculated dependencies of 5 the measured radiation based on single components.

Abstract: Techniques for determining a value of a parameter of interest of a patterning process are described. One such technique involves obtaining a plurality of calibration data units from one or more targets in a metrology process. Each calibration data unit of at least two of the calibration data units represents detected radiation obtained using different respective polarization settings in the metrology process, each polarization setting defining a polarization property of incident radiation of the metrology process and of detected radiation of the metrology process. The calibration data units are used to obtain calibration information about the metrology process. A measurement data unit representing detected radiation scattered from a further target is obtained, the further target having a structure formed using the patterning process on the substrate or on a further substrate. A value of the parameter of interest is determined using the measurement data unit and the obtained calibration information.

Abstract: A method of determining a patterning process parameter from a metrology target, the method including: obtaining a plurality of values of diffraction radiation from the metrology target, each value of the plurality of values corresponding to a different illumination condition of a plurality of illumination conditions of illumination radiation for the target; and using the combination of values to determine a same value of the patterning process parameter for the target.

Abstract: Disclosed is a method of, and associated metrology apparatus for, determining a characteristic of a target on a substrate. The method comprises obtaining a plurality of intensity asymmetry measurements, each intensity asymmetry measurement relating to a target formed on the substrate and determining a sensitivity coefficient corresponding to each target, from the plurality of intensity asymmetry measurements. Using these sensitivity coefficients a representative sensitivity coefficient is determined for said plurality of targets or a subset greater than one thereof. The characteristic of the target can then be determined using the representative sensitivity coefficient.

Abstract: A method of determining a patterning process parameter from a metrology target, the method including: obtaining a plurality of values of diffraction radiation from the metrology target, each value of the plurality of values corresponding to a different illumination condition of a plurality of illumination conditions of illumination radiation for the target; and using the combination of values to determine a same value of the patterning process parameter for the target.

Abstract: Disclosed is a method and associated apparatus of determining a performance parameter (e.g., overlay) of a target on a substrate, and an associated metrology apparatus. The method comprises estimating a set of narrowband measurement values from a set of wideband measurement values relating to the target and determining the performance parameter from said set of narrowband measurement values. The wideband measurement values relate to measurements of the target performed using wideband measurement radiation and may correspond to different central wavelengths. The narrowband measurement values may comprise an estimate of the measurement values which would be obtained from measurement of the target using narrowband measurement radiation having a bandwidth narrower than said wideband measurement radiation.

Abstract: Disclosed is a method, and associated apparatuses, for measuring a parameter of interest relating to a structure having at least two layers. The method comprises illuminating the structure with measurement radiation and detecting scattered radiation having been scattered by said structure. The scattered radiation comprises normal and complementary higher diffraction orders. A scatterometry model which relates a scattered radiation parameter to at least a parameter of interest and an asymmetry model which relates the scattered radiation parameter to at least one asymmetry parameter are defined, the asymmetry parameter relating to one or more measurement system errors and/or an asymmetry in the target other than a misalignment between the two layers. A combination of the scatterometry model and asymmetry model is used to determine a system of equations, and the system of equations is then solved for the parameter of interest.

Abstract: Techniques for determining a value of a parameter of interest of a patterning process are described. One such technique involves obtaining a plurality of calibration data units from one or more targets in a metrology process. Each calibration data unit of at least two of the calibration data units represents detected radiation obtained using different respective polarization settings in the metrology process, each polarization setting defining a polarization property of incident radiation of the metrology process and of detected radiation of the metrology process. The calibration data units are used to obtain calibration information about the metrology process. A measurement data unit representing detected radiation scattered from a further target is obtained, the further target having a structure formed using the patterning process on the substrate or on a further substrate. A value of the parameter of interest is determined using the measurement data unit and the obtained calibration information.

Abstract: An overlay metrology target (600, 900, 1000) contains a plurality of overlay gratings (932-935) formed by lithography. First diffraction signals (740(1)) are obtained from the target, and first asymmetry values (As) for the target structures are derived. Second diffraction signals (740(2)) are obtained from the target, and second asymmetry values (As?) are derived. The first and second diffraction signals are obtained using different capture conditions and/or different designs of target structures and/or bias values. The first asymmetry signals and the second asymmetry signals are used to solve equations and obtain a measurement of overlay error. The calculation of overlay error makes no assumption whether asymmetry in a given target structure results from overlay in the first direction, in a second direction or in both directions. With a suitable bias scheme the method allows overlay and other asymmetry-related properties to be measured accurately, even in the presence of two-dimensional overlay structure.

Abstract: Disclosed is a method of determining a characteristic of interest relating to a structure on a substrate formed by a lithographic process, the method comprising: obtaining an input image of the structure; and using a trained neural network to determine the characteristic of interest from said input image. Also disclosed is a reticle comprising a target forming feature comprising more than two sub-features each having different sensitivities to a characteristic of interest when imaged onto a substrate to form a corresponding target structure on said substrate. Related methods and apparatuses are also described.

Abstract: Disclosed is a method of, and associated metrology apparatus for, determining a characteristic of a target on a substrate. The method comprises obtaining a plurality of intensity asymmetry measurements, each intensity asymmetry measurement relating to a target formed on the substrate and determining a sensitivity coefficient corresponding to each target, from the plurality of intensity asymmetry measurements. Using these sensitivity coefficients a representative sensitivity coefficient is determined for said plurality of targets or a subset greater than one thereof. The characteristic of the target can then be determined using the representative sensitivity coefficient.

Abstract: An overlay metrology target (600, 900, 1000) contains a plurality of overlay gratings (932-935) formed by lithography. First diffraction signals (740(1)) are obtained from the target, and first asymmetry values (As) for the target structures are derived. Second diffraction signals (740(2)) are obtained from the target, and second asymmetry values (As?) are derived. The first and second diffraction signals are obtained using different capture conditions and/or different designs of target structures and/or bias values. The first asymmetry signals and the second asymmetry signals are used to solve equations and obtain a measurement of overlay error. The calculation of overlay error makes no assumption whether asymmetry in a given target structure results from overlay in the first direction, in a second direction or in both directions. With a suitable bias scheme the method allows overlay and other asymmetry-related properties to be measured accurately, even in the presence of two-dimensional overlay structure.

Abstract: A method including: for a metrology target, having a first biased target structure and a second differently biased target structure, created using a patterning process, obtaining metrology data including signal data for the first target structure versus signal data for the second target structure, the metrology data being obtained for a plurality of different metrology recipes and each metrology recipe specifying a different parameter of measurement; determining a statistic, fitted curve or fitted function through the metrology data for the plurality of different metrology recipes as a reference; and identifying at least two different metrology recipes that have a variation of the collective metrology data of the at least two different metrology recipes from a parameter of the reference that crosses or meets a certain threshold.

Abstract: Disclosed is a method, and associated apparatuses, for measuring a parameter of interest relating to a structure having at least two layers. The method comprises illuminating the structure with measurement radiation and detecting scattered radiation having been scattered by said structure. The scattered radiation comprises normal and complementary higher diffraction orders. A scatterometry model which relates a scattered radiation parameter to at least a parameter of interest and an asymmetry model which relates the scattered radiation parameter to at least one asymmetry parameter are defined, the asymmetry parameter relating to one or more measurement system errors and/or an asymmetry in the target other than a misalignment between the two layers. A combination of the scatterometry model and asymmetry model is used to determine a system of equations, and the system of equations is then solved for the parameter of interest.

Abstract: Disclosed is a method and associated apparatus of determining a performance parameter (e.g., overlay) of a target on a substrate, and an associated metrology apparatus. The method comprises estimating a set of narrowband measurement values from a set of wideband measurement values relating to the target and determining the performance parameter from said set of narrowband measurement values. The wideband measurement values relate to measurements of the target performed using wideband measurement radiation and may correspond to different central wavelengths. The narrowband measurement values may comprise an estimate of the measurement values which would be obtained from measurement of the target using narrowband measurement radiation having a bandwidth narrower than said wideband measurement radiation.

Abstract: A method including: for a metrology target, having a first biased target structure and a second differently biased target structure, created using a patterning process, obtaining metrology data including signal data for the first target structure versus signal data for the second target structure, the metrology data being obtained for a plurality of different metrology recipes and each metrology recipe specifying a different parameter of measurement; determining a statistic, fitted curve or fitted function through the metrology data for the plurality of different metrology recipes as a reference; and identifying at least two different metrology recipes that have a variation of the collective metrology data of the at least two different metrology recipes from a parameter of the reference that crosses or meets a certain threshold.

Abstract: A method of determining a patterning process parameter from a metrology target, the method including: obtaining a plurality of values of diffraction radiation from the metrology target, each value of the plurality of values corresponding to a different illumination condition of a plurality of illumination conditions of illumination radiation for the target; and using the combination of values to determine a same value of the patterning process parameter for the target.

Abstract: An overlay metrology target (600, 900, 1000) contains a plurality of overlay gratings (932-935) formed by lithography. First diffraction signals (740(1)) are obtained from the target, and first asymmetry values (As) for the target structures are derived. Second diffraction signals (740(2)) are obtained from the target, and second asymmetry values (As?) are derived. The first and second diffraction signals are obtained using different capture conditions and/or different designs of target structures and/or bias values. The first asymmetry signals and the second asymmetry signals are used to solve equations and obtain a measurement of overlay error. The calculation of overlay error makes no assumption whether asymmetry in a given target structure results from overlay in the first direction, in a second direction or in both directions. With a suitable bias scheme the method allows overlay and other asymmetry-related properties to be measured accurately, even in the presence of two-dimensional overlay structure.