Patent ID: 11880142
Assignee: KLA CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 9:
10. The self-calibrating overlay metrology system of claim 1, wherein generating corrected overlay measurements for the plurality of device targets by adjusting the preliminary device overlay measurements based on the self-calibrating assist overlay measurements comprises:
comparing the preliminary device overlay measurements with the self-calibrating assist overlay measurements based on one or more statistical metrics;
generating a quality metric associated with the one or more statistical metrics;
correcting the preliminary device overlay measurements to compensate for differences between the one or more statistical metrics if the quality metric is below a selected threshold; and
retraining the overlay recipe using the self-calibrating assist overlay measurements and generating the corrected overlay measurements based on the overlay recipe after retraining if the quality metric is equal to or above a selected threshold.