Displacement based overlay or alignment
AssigneeASML Netherlands B.V.
InventorsMarinus Jochemsen, Scott Anderson Middlebrooks, Stefan Hunsche, Te-Sheng Wang
Life of this patent
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Abstract
A method including obtaining an image of a plurality of structures on a substrate, wherein each of the plurality of structures is formed onto the substrate by transferring a corresponding pattern of a design layout; obtaining, from the image, a displacement for each of the structures with respect to a reference point for that structure; and assigning each of the structures into one of a plurality of groups based on the displacement.
Claims21
A method comprising:
- obtaining an image of a plurality of structures on a substrate, wherein each structure of the plurality of structures is formed onto the substrate by transferring a corresponding pattern of a design layout;
- obtaining, from the image, a displacement for each of the structures with respect to a reference point for that structure, wherein the displacement corresponds to a shift of a center, centroid or center of mass of that structure and wherein the reference point for that structure is a common reference point, for the structures, within a two dimensional field that spans the structures together or is a reference point from a plurality of spatially-separated reference points, for the structures, within a two dimensional field that spans the structures together;
- and
- assigning, using a hardware computer system, each of the structures into one of a plurality of groups based on the displacement.
A computer program product comprising a non-transitory computer readable medium having instructions recorded thereon, the instructions when executed by a computer system, configured to cause the computer system to at least:
- obtain an image of a plurality of structures on a substrate, wherein each of the plurality of structures is formed onto the substrate by transferring a corresponding pattern of a design layout;
- obtain, from the image, a displacement for each of the structures with respect to a reference point for that structure, wherein the displacement corresponds to a shift of a center, centroid or center of mass of that structure and wherein the reference point for that structure is a common reference point, for the structures, within a two dimensional field that spans the structures together or is a reference point from a plurality of spatially-separated reference points, for the structures, within a two dimensional field that spans the structures together;
- and
- assign each of the structures into one of a plurality of groups based on the displacement.
A computer program product comprising a non-transitory computer readable medium having instructions recorded thereon, the instructions when executed by a computer system, configured to cause the computer system to at least:
- obtain an image of a plurality of structures on a substrate, wherein each of the plurality of structures is formed onto the substrate by transferring a corresponding pattern of a design layout;
- obtain, from the image, a displacement for each of the structures with respect to a reference point for that structure;
- and
- assign each of the structures into one of a plurality of groups based on the displacement,
- wherein the structures assigned to a same group are able to be linearly mapped to their respective corresponding patterns with a same linear transformation or mapping.
Dependencies are inferred from the claim text.