Patent ID: 8237914

Claim:
A process for creating first and second overlapping patterns on a target field of a substrate, comprising: determining overlay errors, caused by local residual distortion in a patterning device, between the first and second overlapping patterns associated with the patterning device, the determined overlay errors corresponding to controlling the process according to a suggested value for each of at least one process parameter of a model of the process; determining a value for the each of the at least one process parameter corresponding to minimal overlay errors by fitting the model to data comprising the determined overlay errors and the suggested value for the each of the at least one process parameter; determining local residual overlay errors between respective portions of the first and second patterns based at least on the determined values for the each of the at least one process parameter; creating the first and second patterns on the target field of the substrate; and applying, in parallel with the creating, dynamic intra-field corrections to the determined values for the each of the at least one process parameter based on the local residual overlay errors such that a first part of the first pattern is created according to first determined values for the each of the at least one process parameter and a second part of the first pattern is created according to second determined values for the each of the at least one process parameter, wherein the first values differ from the second values.