Abstract: Methods and systems for providing overlay corrections are provided. A method may include: selecting an overlay model configured to perform overlay modeling for a wafer; obtaining a first set of modeled results from the overlay model, the first set of modeled results indicating adjustments applicable to a plurality of term coefficients of the overlay model; calculating a significance matrix indicating the significance of the plurality of term coefficients; identifying at least one less significant term coefficient among the plurality of term coefficients based on the calculated significance matrix; obtaining a second set of modeled results from the overlay model, the second set of modeled results indicating adjustments applicable to the plurality of term coefficients except for the identified at least one less significant term coefficient; and providing the second set of modeled results to facilitate overlay correction.

Abstract: A process control system includes a controller configured to generate a reference overlay signature based on one or more overlay reference layers of a sample, extrapolate the reference overlay signature to a set of correctable fields for the exposure of a current layer of the sample to generate a full-field reference overlay signature, identify one or more alignment fields of the set of correctable fields, generate an alignment-correctable signature by modeling alignment corrections for the set of correctable fields, subtract the alignment-correctable signature from the full-field reference overlay signature to generate feedforward overlay corrections for the current layer when the one or more overlay reference layers are the same as the one or more alignment reference layers, generate lithography tool corrections based on the feedforward overlay corrections, and provide the lithography tool corrections for the current layer to the lithography tool.

Abstract: A process control system includes a controller configured to generate a reference overlay signature based on one or more overlay reference layers of a sample, extrapolate the reference overlay signature to a set of correctable fields for the exposure of a current layer of the sample to generate a full-field reference overlay signature, identify one or more alignment fields of the set of correctable fields, generate an alignment-correctable signature by modeling alignment corrections for the set of correctable fields, subtract the alignment-correctable signature from the full-field reference overlay signature to generate feedforward overlay corrections for the current layer when the one or more overlay reference layers are the same as the one or more alignment reference layers, generate lithography tool corrections based on the feedforward overlay corrections, and provide the lithography tool corrections for the current layer to the lithography tool.

Abstract: Methods and systems for providing overlay corrections are provided. A method may include: selecting an overlay model configured to perform overlay modeling for a wafer; obtaining a first set of modeled results from the overlay model, the first set of modeled results indicating adjustments applicable to a plurality of term coefficients of the overlay model; calculating a significance matrix indicating the significance of the plurality of term coefficients; identifying at least one less significant term coefficient among the plurality of term coefficients based on the calculated significance matrix; obtaining a second set of modeled results from the overlay model, the second set of modeled results indicating adjustments applicable to the plurality of term coefficients except for the identified at least one less significant term coefficient; and providing the second set of modeled results to facilitate overlay correction.