CPC G03F 7/70625 (2013.01) | 20 Claims |
1. 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.
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