{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-10520451","patent":{"patent_number":"US-10520451","title":"Diffraction based overlay metrology tool and method of diffraction based overlay metrology","assignee":null,"inventors":[],"filing_date":"2017-08-22T00:00:00.000Z","publication_date":"2019-12-31T00:00:00.000Z","cpc_codes":["G01N"],"num_claims":16,"abstract":"Systems, methods, and apparatus are provided for determining overlay of a pattern on a substrate with a mask pattern defined in a resist layer on top of the pattern on the substrate. A first grating is provided under a second grating, each having substantially identical pitch to the other, together forming a composite grating. A first illumination beam is provided under an angle of incidence along a first horizontal direction. The intensity of a diffracted beam from the composite grating is measured. A second illumination beam is provided under the angle of incidence along a second horizontal direction. The second horizontal direction is opposite to the first horizontal direction. The intensity of the diffracted beam from the composite grating is measured. The difference between the diffracted beam from the first illumination beam and the diffracted beam from the second illumination beam, linearly scaled, results in the overlay error."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Diffraction based overlay metrology tool and method of diffraction based overlay metrology","description":"Systems, methods, and apparatus are provided for determining overlay of a pattern on a substrate with a mask pattern defined in a resist layer on top of the pattern on the substrate. A first grating i","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-10520451","license":"CC-BY-4.0-like","license_terms":"AI-generated analysis on this page (summary, layman_explanation, technical_analysis, business_analysis, faqs) may be reused with attribution and a visible link back to the canonical URL above. Patent abstracts, claims, and bibliographic data are USPTO public domain.","required_link":"https://patentable.app/patents/US-10520451","citation_suggestion":"Patentable. \"Diffraction based overlay metrology tool and method of diffraction based overlay metrology\" (US-10520451). https://patentable.app/patents/US-10520451","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-10520451","json":"https://patentable.app/api/llm-context/US-10520451","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-05-31T16:50:29.499Z"}