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 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: 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 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 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 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 device manufacturing method includes: forming a layer on a substrate by a layer-forming process; determining a value of a metric at a plurality of positions across the substrate, wherein variation of the values across the substrate is indicative of variation of layer thickness across the substrate; controlling the layer-forming parameter based on the values so as to reduce variation of layer thickness in a subsequent layer-forming process on a different substrate; and repeating the layer-forming process on a different substrate according to the controlled layer-forming parameter.

Abstract: A method of measuring a property of a substrate, the substrate having a plurality of targets formed thereon, the method comprising: measuring N targets of the plurality of targets using an optical measurement system, where N is an integer greater than 2 and each of said N targets is measured Wt times, where Wt is an integer greater than 2 so as to obtain N*Wt measurement values; and determining R property values using Q equations and the N*Wt measurement values, where R<Q?N*Wt; wherein the optical measurement system has at least one changeable setting and, for each of the N targets, measurement values are obtained using different setting values of at least one changeable setting.

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: 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 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 of measuring a property of a substrate, the substrate having a plurality of targets formed thereon, the method comprising: measuring N targets of the plurality of targets using an optical measurement system, where N is an integer greater than 2 and each of said N targets is measured Wt times, where Wt is an integer greater than 2 so as to obtain N*Wt measurement values; and determining R property values using Q equations and the N*Wt measurement values, where R<Q?N*Wt; wherein the optical measurement system has at least one changeable setting and, for each of the N targets, measurement values are obtained using different setting values of at least one changeable setting.

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.