Method and apparatus for analyzing the state of generation of foreign particles in semiconductor fabrication process
Patent 5463459 Issued on October 31, 1995. Estimated Expiration Date: 
April 16, 2013. 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.
April 16, 2013. 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 ReferencesAutomatic photomask inspection method and system Production system for manufacturing semiconductor devices Spatial filter for optically based defect inspection system Method and apparatus for inspecting foreign particles on real time basis in semiconductor mass production line Adaptive spatial filter for surface inspection Patent #: 5276498 Inventors
AssigneeApplicationNo. 046720 filed on 04/16/1993US Classes:356/237.5, On patterned or topographical surface (e.g., wafer, mask, circuit board)257/E21.53, For structural parameters, e.g., thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions (EPO)438/16Optical characteristic sensedExaminersPrimary: McGraw, Vincent P.Attorney, Agent or FirmInternational ClassesG01N 021/89G02B 027/46 G06F 015/46 Foreign Application Priority Data1992-04-17 JPAbstractA defect detecting apparatus including an illumination system for radiating a light of a plane wave linearly to a substrate having repetitive patterns of different pitches; a focusing optical system for focusing a light image reflected from the substrate thus illuminated by the illumination system; a spatial filter disposed intermediate the focusing optical system so as to shield a diffraction light from repetitive patterns of a small pitch on the substrate; a detector for detecting the light image formed by the focusing optical system; an erasing means for comparing and erasing signals which are generated on the basis of repetitive patterns of a large pitch and obtained through the spatial filter, out of signals detected by the detector; and a defect detecting means for detecting defects on the substrate in accordance with a signal detected by the detector, as well as a method applied to the said apparatus. | |
