Patent ID: 11862522
Assignee: nan
Field: Optics (Instruments)
Classification: CPC H  G | IPC G  H

Claim 4:
5. A method comprising:
selecting, using a processing unit, a plurality of measurement setups for a corresponding plurality of wafer regions, wherein the wafer regions are pre-determined or determined on-the-fly;
carrying out metrology measurements with one of the selected measurement setups for each corresponding wafer region using an optical metrology tool that includes the processing unit, an optical illumination source, and optical elements, wherein the metrology measurements are on a plurality of metrology targets on one or more wafers;
symmetrizing pixel values in pupil images of the wafer regions using the processing unit;
modifying at least one pixel value according to an average of neighboring pixel values using the processing unit thereby reducing noise in the pupil images;
concatenating pixels from the metrology measurements using different of the measurement setups using the processing unit;
determining metrology metric values from the concatenated pixels using the processing unit; and
weighting the concatenated pixels using the processing unit; and
determining measurement stability using the processing unit by comparing results from concatenations of different sub-sets of the metrology measurements.