Surface inspection using laser triangulation
AssigneeOnto Innovation Inc.
InventorsJian Ding, Min Yang
Life of this patent
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Abstract
Techniques for inspecting a substrate can include scanning the substrate across a plurality of scan positions using an interrogation beam having a width substantially equal to or greater than a diameter of at least one surface feature on a surface of the substrate to generate scanning results. A set of raw centroid calculation results can be generated based on the scanning results. An error property can be determined and removed from the raw centroid calculation results to generated refined centroid calculation results. A characteristic of the surface feature can be determined based on the centroid calculation results.
Claims20
A method for inspecting a substrate, the method comprising:
- scanning the substrate across a plurality of scan positions using an interrogation beam having a width substantially equal to or greater than a diameter of at least one surface feature on a surface of the substrate to generate scanning results;
- generating a set of raw centroid calculation results based on the scanning results;
- determining an error property in the raw centroid calculation results;
- removing the error property from the raw centroid calculation results to generate refined centroid calculation results;
- and
- determining a characteristic of the at least one surface feature based on the refined centroid calculation results.
An inspection system comprising:
- a light source to scan a substrate across a plurality of scan positions using an interrogation beam having a width substantially equal to or greater than a diameter of at least one surface feature on a surface of the substrate to generate scanning results;
- and
- at least one processor to:
- generate a set of raw centroid calculation results based on the scanning results;
- determine an error property in the raw centroid calculation results;
- remove the error property from the raw centroid calculation results to generate refined centroid calculation results;
- and
- determine a characteristic of the at least one surface feature based on the refined centroid calculation results.
A machine-storage medium embodying instructions that, when executed by a machine, cause the machine to perform operations comprising:
- scanning a substrate across a plurality of scan positions using an interrogation beam having a width substantially equal to or greater than a diameter of at least one surface feature on a surface of the substrate to generate scanning results;
- generating a set of raw centroid calculation results based on the scanning results;
- determining an error property in the raw centroid calculation results;
- removing the error property from the raw centroid calculation results to generate refined centroid calculation results;
- and
- determining a characteristic of the at least one surface feature based on the refined centroid calculation results.
Dependencies are inferred from the claim text.