Metrology method and associated metrology and lithographic apparatuses
AssigneeASML Netherlands B.V.
InventorsPatricius Aloysius Jacobus Tinnemans, Leendert Jan Karssemeijer
Life of this patent
Estimating the term…
Abstract
Disclosed is a method of determining a substrate deformation metric relating to at least one substrate, the substrate deformation metric describing deformation across the at least one substrate. The method comprises obtaining alignment data relating to measurement of a plurality of structures on said substrate using a plurality of illumination conditions; and determining substrate deformation metric values for the substrate deformation metric which minimizes the number of basis vectors which are required to expand dispersion due to structure deformation of said plurality of structures.
Claims18
A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a system to cause the system to perform operations for generating a substrate deformation metric relating to a substrate using an alignment sensor, the operations comprising:
- controlling the alignment sensor to obtain alignment data relating to measurement of a plurality of structures on said substrate using a plurality of illumination conditions;
- and
- determining substrate deformation metric values for the substrate deformation metric which minimizes the number of basis vectors which are required to expand dispersion due to structure deformation of said plurality of structures.
The non-transitory computer-readable medium of 1, wherein determining substrate deformation metric values further comprises estimating the substrate deformation metric values and using the estimated substrate deformation metric values.
The non-transitory computer-readable medium of 10, wherein estimating the substrate deformation metric values comprises performing more than one iterations of the controlling and determining operations, and in each iteration after a first iteration, using the determined substrate deformation metric values output from a previous iteration as the estimated substrate deformation metric values.
The non-transitory computer-readable medium of 13, wherein the operations further comprise determining an alignment correction for a subsequent lithographic exposure based on the determined substrate deformation metric values.
A lithographic apparatus comprising:
- a patterning device support for supporting a patterning device;
- a substrate support for supporting a substrate;
- an alignment sensor for obtaining the alignment data;
- and
- one or more processors configured to execute instructions to cause the lithographic apparatus to perform operations for generating a substrate deformation metric relating to the substrate using the alignment sensor, the operations comprising:
- controlling the alignment sensor to obtain alignment data relating to measurement of a plurality of structures on said substrate using a plurality of illumination conditions;
- and
- determining substrate deformation metric values for the substrate deformation metric which minimizes the number of basis vectors which are required to expand dispersion due to structure deformation of said plurality of structures.
Dependencies are inferred from the claim text.