Metrology method and associated metrology and lithographic apparatuses
AssigneeASML Netherlands B.V.
InventorSarathi Roy
Life of this patent
Estimating the term…
Abstract
A method to determine a performance indicator indicative of alignment performance of a processed substrate. The method includes obtaining measurement data including a plurality of measured position values of alignment marks on the substrate and calculating a positional deviation between each measured position value and a respective expected position value. These positional deviations are used to determine a directional derivative between the alignment marks, and the directional derivatives are used to determine at least one directional derivative performance indicator.
Claims20
A method to determine a performance indicator indicative of alignment performance of a processed substrate, the method comprising:
- obtaining measurement data comprising a plurality of measured position values of alignment marks on the substrate;
- calculating a positional deviation between each measured position value and a respective expected position value;
- determining a directional derivative between the alignment marks using the positional deviations, the directional derivative representing a change of the positional deviations per unit distance;
- and
- using the directional derivative to determine at least one directional derivative performance indicator.
A non-transient computer program carrier comprising a computer program therein, the computer program, upon execution by an apparatus, configured to cause the apparatus to at least:
- obtain measurement data comprising a plurality of measured position values of alignment marks on a substrate;
- calculate a positional deviation between each measured position value and a respective expected position value;
- determine a directional derivative between the alignment marks using the positional deviations, the directional derivative representing a rate of change of the positional deviations per unit distance;
- and
- use the directional derivative to determine at least one directional derivative performance indicator indicative of alignment performance.
Dependencies are inferred from the claim text.