A method of forming an integrated circuit includes the following steps. A substrate including a plurality of exposure fields is provided, and each of the exposure field includes a target portion and a set of alignment marks. Measure the set of alignment marks of each exposure field by a measuring system to obtain alignment data for the respective exposure field. Determine an exposure parameter corresponding to each exposure field and an exposure location on the target portion from the alignment data for the respective exposure field by a calculating system. Feedback the alignment data to a next substrate.

Methods for in-die overlay reticle measurement and the resulting devices are disclosed. Embodiments include providing parallel structures in a first layer on a substrate; determining measurement sites, in a second layer above the first layer, void of active integrated circuit elements; forming overlay trenches, in the measurement sites and parallel to the structures, exposing sections of the structures, wherein each overlay trench is aligned over a structure and over spaces between the structure and adjacent structures; determining a trench center-of-gravity of an overlay trench; determining a structure center-of-gravity of a structure exposed in the overlay trench; and determining an overlay parameter based on a difference between the trench center-of-gravity and the structure center-of-gravity.

A system comprises a topography measurement system configured to determine a respective height for each of a plurality of locations on a substrate; and a processor configured to: determine a height map for the substrate based on the determined heights for the plurality of locations; and determine at least one alignment parameter for the substrate by comparing the height map and a reference height map, wherein the reference height map comprises or represents heights for a plurality of locations on a reference substrate portion.

An overlay measurement and correction method and device is provided. In an embodiment the measurement device takes measurements of a first semiconductor wafer and uses the measurements in a plurality of correction techniques to generate an overlay correction model. The plurality of correction techniques include a first order correction, a first intra-field high order parameter correction and a first inter-field high order parameter correction. The model is used to adjust the exposure parameters for the exposure of the next semiconductor wafer. The process is repeated on each semiconductor wafer for a run-to-run analysis.

A method of determining a measurement subset of metrology point locations which includes a subset of potential metrology point locations on a substrate. The method including identifying a plurality of candidate metrology point locations from the potential metrology point locations. A change in the level of informativity imparted by the measurement subset of metrology point locations which is attributable to the inclusion of that candidate metrology point location into the measurement subset of metrology point locations is evaluated for each of the candidate metrology point locations. The candidate metrology point locations which have the greatest increase in the level of informativity attributed thereto are selected for inclusion into the measurement subset of metrology point locations.

A method of determining overlay of a patterning process, the method including: illuminating a substrate with a radiation beam such that a beam spot on the substrate is filled with one or more physical instances of a unit cell, the unit cell having geometric symmetry at a nominal value of overlay; detecting primarily zeroth order radiation redirected by the one or more physical instances of the unit cell using a detector; and determining, by a hardware computer system, a non-nominal value of overlay of the unit cell from values of an optical characteristic of the detected radiation.

A masking process and a mask set. The masking process includes: aligning a first mask with a stage carrying a substrate to be patterned; forming a first layer structure and a first overlay correction pattern on the substrate to be patterned by using the first mask; correcting with an image sensor and the first overlay correction pattern; aligning a second mask with the stage; forming a second layer structure and a second overlay correction pattern on the substrate to be patterned by using the second mask; and correcting with the image sensor and the second overlay correction pattern.

A method of determining overlay of a patterning process, the method including: obtaining a detected representation of radiation redirected by one or more physical instances of a unit cell, wherein the unit cell has geometric symmetry at a nominal value of overlay and wherein the detected representation of the radiation was obtained by illuminating a substrate with a radiation beam such that a beam spot on the substrate was filled with the one or more physical instances of the unit cell; and determining, from optical characteristic values from the detected radiation representation, a value of a first overlay for the unit cell separately from a second overlay for the unit cell that is also obtainable from the same optical characteristic values, wherein the first overlay is in a different direction than the second overlay or between a different combination of parts of the unit cell than the second overlay.

A method of aligning a substrate within an apparatus. The method includes determining a substrate grid based on measurements of a plurality of targets, each at different locations on a substrate. The determining includes repetitions of updating the substrate grid after each measurement of a target, and using the updated grid to align a measurement of a subsequent target.

A method of determining a parameter of a patterning process, the method including: obtaining a detected representation of radiation redirected by a structure having geometric symmetry at a nominal physical configuration, wherein the detected representation of the radiation was obtained by illuminating a substrate with a radiation beam such that a beam spot on the substrate was filled with the structure; and determining, by a hardware computer system, a value of the patterning process parameter based on optical characteristic values from an asymmetric optical characteristic distribution portion of the detected radiation representation with higher weight than another portion of the detected radiation representation, the asymmetric optical characteristic distribution arising from a different physical configuration of the structure than the nominal physical configuration.