Method for inferring a local uniformity metric
AssigneeASML Netherlands B. V.
InventorsSimon Gijsbert Josephus Mathijssen, Kaustuve Bhattacharyya
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Abstract
A method of inferring a value for at least one local uniformity metric relating to a product structure, the method including: obtaining intensity data including an intensity image relating to at least one diffraction order obtained from a measurement on a target; obtaining at least one intensity distribution from the intensity image; determining, from the at least one intensity distribution, an intensity indicator expressing a variation of either intensity over the at least one diffraction order, or a difference in intensity between two complimentary diffraction orders over the intensity image; and inferring the value for the at least one local uniformity metric from the intensity indicator.
Claims20
A method of inferring a value for at least one local uniformity metric relating to a product structure, the method comprising:
- obtaining intensity data comprising an intensity image relating to at east one diffraction order obtained from a measurement on a target;
- obtaining at least one intensity statistical distribution from the intensity image;
- determining, from the at least one intensity statistical distribution, an intensity indicator expressing a variation of either a) intensity over the at least one diffraction order, or b) a difference in intensity between two complimentary diffraction orders over the intensity image;
- and
- inferring, by a hardware computer, the value for the at least one local uniformity metric from the intensity indicator.
A computer program product comprising a non-transitory machine-readable medium comprising machine readable instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
- obtain intensity data comprising an intensity image relating to at least one diffraction order obtained from a measurement on a target;
- obtain at least one intensity statistical distribution from the intensity image;
- determine, from the at least one intensity statistical distribution, an intensity indicator expressing a variation of either intensity over the at least one diffraction order, or a difference in intensity between two complimentary diffraction orders over the intensity image;
- and
- infer a value for at least one local uniformity metric relating to a product structure from the intensity indicator.
Dependencies are inferred from the claim text.