Abstract: Disclosed is a method of determining a characteristic of interest, in particular focus, relating to a structure on a substrate formed by a lithographic process, and an associated patterning device and lithographic system. The method comprises forming a modified substrate feature on the substrate using a corresponding modified reticle feature on a patterning device, the modified substrate feature being formed for a primary function other than metrology, more specifically for providing a support for a vertically integrated structure. The modified reticle feature is such that said modified substrate feature is formed with a geometry dependent on the characteristic of interest during formation. The modified substrate feature can be measured to determine said characteristic of interest.

Abstract: A lithographic apparatus prints a focus metrology pattern (T) on a substrate, the printed pattern including at least a first array of features (800). Features at any location within the array define a pattern that repeats at in at least a first direction of periodicity (X), while geometric parameters of the repeating pattern (w1, w3) vary over the array. A focus measurement is derived from measurements of the array at a selected subset of locations (ROI). As a result, the geometric parameters upon which the measurement of focus performance is based can be optimized by selection of locations within the array. The need to optimize geometric parameters of a target design on a reticle (MA) is reduced or eliminated. The measured property may be asymmetry, for example, and/or diffraction efficiency. The measured property for all locations may be captured by dark-field imaging, and a subset of locations selected after capture.

Abstract: A focus metrology target includes one or more periodic arrays of features. A measurement of focus performance of a lithographic apparatus is based at least in part on diffraction signals obtained from the focus metrology target. Each periodic array of features includes a repeating arrangement of first zones interleaved with second zones, a feature density being different in the first zones and the second zones. Each first zone includes a repeating arrangement of first features. A minimum dimension of each first feature is close to but not less than a resolution limit of the printing by the lithographic apparatus, so as to comply with a design rule in a given a process environment. A region of high feature density may further include a repeating arrangement of larger features.

Abstract: A lithographic apparatus prints a focus metrology pattern (T) on a substrate, the printed pattern including at least a first array of features (800). Features at any location within the array define a pattern that repeats at in at least a first direction of periodicity (X), while geometric parameters of the repeating pattern (w1, w3) vary over the array. A focus measurement is derived from measurements of the array at a selected subset of locations (ROI). As a result, the geometric parameters upon which the measurement of focus performance is based can be optimized by selection of locations within the array. The need to optimize geometric parameters of a target design on a reticle (MA) is reduced or eliminated. The measured property may be asymmetry, for example, and/or diffraction efficiency. The measured property for all locations may be captured by dark-field imaging, and a subset of locations selected after capture.

Abstract: Disclosed is a method of determining a characteristic of interest, in particular focus, relating to a structure on a substrate formed by a lithographic process, and an associated patterning device and lithographic system. The method comprises forming a modified substrate feature on the substrate using a corresponding modified reticle feature on a patterning device, the modified substrate feature being formed for a primary function other than metrology, more specifically for providing a support for a vertically integrated structure. The modified reticle feature is such that said modified substrate feature is formed with a geometry dependent on the characteristic of interest during formation. The modified substrate feature can be measured to determine said characteristic of interest.

Abstract: A focus metrology target includes one or more periodic arrays of features. A measurement of focus performance of a lithographic apparatus is based at least in part on diffraction signals obtained from the focus metrology target. Each periodic array of features includes a repeating arrangement of first zones interleaved with second zones, a feature density being different in the first zones and the second zones. Each first zone includes a repeating arrangement of first features. A minimum dimension of each first feature is close to but not less than a resolution limit of the printing by the lithographic apparatus, so as to comply with a design rule in a given a process environment. A region of high feature density may further include a repeating arrangement of larger features.

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: 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.