Method and apparatus for detecting patterns
Patent 5153444 Issued on October 6, 1992. Estimated Expiration Date: 
January 14, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
January 14, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesMethod of inspecting microscopic surface defects Automatic focusing method and apparatus utilizing contrasts of projected pattern Pattern defect inspection apparatus Method of and apparatus for checking geometry of multi-layer patterns for IC structures Patent #: 4791586 InventorsAssigneeApplicationNo. 641001 filed on 01/14/1991US Classes:250/559.05, With imaging250/559.39, With comparison to reference or standard250/559.45, With defect discrimination circuitry356/394With comparison to master, desired shape, or reference voltageExaminersPrimary: Nelms, David C.Assistant: Shami, F. Attorney, Agent or FirmForeign Patent References
International ClassG01N 021/88Foreign Application Priority Data1989-09-18 JPAbstractA method and apparatus for detecting a defect in a circuit pattern by detecting a gray image signal from each of a plurality of circuit patterns as objects of inspection, which circuit patterns have been fabricated so as to be identical with one another, and detecting a defect as a difference of edge position between two circuit patterns by comparing the detected gray image signal of one circuit pattern with the detected gray image signal of another circuit pattern. | |
