Abstract: Multilayered product structures are formed on substrates by a combination of patterning steps, physical processing steps and chemical processing steps. An inspection apparatus illuminates a plurality of target structures and captures pupil images representing the angular distribution of radiation scattered by each target structure. The target structures have the same design but are formed at different locations on a substrate and/or on different substrates. Based on a comparison of the images the inspection apparatus infers the presence of process-induced stack variations between the different locations. In one application, the inspection apparatus separately measures overlay performance of the manufacturing process based on dark-field images, combined with previously determined calibration information. The calibration is adjusted for each target, depending on the stack variations inferred from the pupil images.

Abstract: An inspection apparatus (140) measures asymmetry or other property of target structures (T) formed by a lithographic process on a substrate. For a given set of illumination conditions, accuracy of said measurement is influenced strongly by process variations across the substrate and/or between substrates. The apparatus is arranged to collect radiation scattered by a plurality of structures under two or more variants of said illumination conditions (p1?, p1, p1+; ?1?, ?1, ?1+). A processing system (PU) is arranged to derive the measurement of said property using radiation collected under a different selection or combination of said variants for different ones of said structures. The variants may be for example in wavelength, or in angular distribution, or in any characteristic of the illumination conditions. Selection and/or combination of variants is made with reference to a signal quality (302, Q, A) observed in the different variants.

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: 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: An inspection apparatus (140) measures asymmetry or other property of target structures (T) formed by a lithographic process on a substrate. For a given set of illumination conditions, accuracy of said measurement is influenced strongly by process variations across the substrate and/or between substrates. The apparatus is arranged to collect radiation scattered by a plurality of structures under two or more variants of said illumination conditions (p1?, p1, p1+; ?1?, ?1, ?1+). A processing system (PU) is arranged to derive the measurement of said property using radiation collected under a different selection or combination of said variants for different ones of said structures. The variants may be for example in wavelength, or in angular distribution, or in any characteristic of the illumination conditions. Selection and/or combination of variants is made with reference to a signal quality (302, Q, A) observed in the different variants.

Abstract: Disclosed is a process monitoring method, and an associated metrology apparatus.

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 inspection apparatus (140) measures asymmetry or other property of target structures (T) formed by a lithographic process on a substrate. For a given set of illumination conditions, accuracy of said measurement is influenced strongly by process variations across the substrate and/or between substrates. The apparatus is arranged to collect radiation scattered by a plurality of structures under two or more variants of said illumination conditions (p1?, p1, p1+; ?1?, ?1, ?1+). A processing system (PU) is arranged to derive the measurement of said property using radiation collected under a different selection or combination of said variants for different ones of said structures. The variants may be for example in wavelength, or in angular distribution, or in any characteristic of the illumination conditions. Selection and/or combination of variants is made with reference to a signal quality (302, Q, A) observed in the different variants.

Abstract: Disclosed is a process monitoring method, and an associated metrology apparatus.

Abstract: Disclosed is a process monitoring method, and an associated metrology apparatus. The method comprises: comparing measured target response spectral sequence data relating to the measurement response of actual targets to equivalent reference target response sequence data relating to a measurement response of the targets as designed; and performing a process monitoring action based on the comparison of said measured target response sequence data and reference target response sequence data. The method may also comprise determining stack parameters from the measured target response spectral sequence data and reference target response spectral sequence data.

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: Multilayered product structures are formed on substrates by a combination of patterning steps, physical processing steps and chemical processing steps. An inspection apparatus illuminates a plurality of target structures and captures pupil images representing the angular distribution of radiation scattered by each target structure. The target structures have the same design but are formed at different locations on a substrate and/or on different substrates. Based on a comparison of the images the inspection apparatus infers the presence of process-induced stack variations between the different locations. In one application, the inspection apparatus separately measures overlay performance of the manufacturing process based on dark-field images, combined with previously determined calibration information. The calibration is adjusted for each target, depending on the stack variations inferred from the pupil images.

Abstract: Disclosed is a process monitoring method, and an associated metrology apparatus. The method comprises: comparing measured target response spectral sequence data relating to the measurement response of actual targets to equivalent reference target response sequence data relating to a measurement response of the targets as designed; and performing a process monitoring action based on the comparison of said measured target response sequence data and reference target response sequence data. The method may also comprise determining stack parameters from the measured target response spectral sequence data and reference target response spectral sequence data.

Abstract: An inspection apparatus (140) measures asymmetry or other property of target structures (T) formed by a lithographic process on a substrate. For a given set of illumination conditions, accuracy of said measurement is influenced strongly by process variations across the substrate and/or between substrates. The apparatus is arranged to collect radiation scattered by a plurality of structures under two or more variants of said illumination conditions (p1?, p1, p1+; ?1?, ?1, ?1+). A processing system (PU) is arranged to derive the measurement of said property using radiation collected under a different selection or combination of said variants for different ones of said structures. The variants may be for example in wavelength, or in angular distribution, or in any characteristic of the illumination conditions. Selection and/or combination of variants is made with reference to a signal quality (302, Q, A) observed in the different variants.