Method of focus metrology
AssigneeASML Netherlands B.V.
InventorWim Tjibbo TEL
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Abstract
The present invention provides a method of focus metrology. The method comprises using an inspection tool to image a sample having a plurality of features formed by a lithography tool; determining the amount of shift of the plurality of features in the image of the sample in comparison to a design layout; and deriving a focus value of the lithography tool based on the amount of shift.
Claims20
A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out operations for focus metrology, the operations comprising:
- imaging, using an inspection tool or a metrology tool, a sample having a plurality of features formed by a lithography tool;
- determining an amount of shift of the plurality of features in an image of the sample in comparison to a design layout;
- and
- deriving a focus value of the lithography tool based on the amount of shift.
A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out operations of focus metrology, the operations comprising:
- imaging, using an inspection tool or a metrology tool, a sample having a plurality of features formed by a lithography tool;
- determining an error in placement of the plurality of features in the image of the sample in comparison to the placement position of the plurality of features in a design layout;
- and
- deriving a focus value of the lithography tool based on the error in placement.
Dependencies are inferred from the claim text.