Sample inspection system
December 27, 2021. 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 ReferencesApparatus for reflectance measurement of fluorescent radiation and composite useful therein Method of inspecting microscopic surface defects Apparatus for continuously measuring the degree of milling of grains Horizontal position detecting device Position detecting system Apparatus and method for detecting defects and dust on a patterned surface Foreign particle detecting method and apparatus Surface pit detection system and method Apparatus for separating specular from diffuse radiation Particle detection on patterned wafers and the like InventorsApplicationNo. 10/033069 filed on 12/27/2001US Classes:356/237.4, On patterned or topographical surface (e.g., wafer, mask, circuit board)356/237.5On patterned or topographical surface (e.g., wafer, mask, circuit board)ExaminersPrimary: Pham, Hoa Q.Attorney, Agent or FirmInternational ClassesG01N 21/47 (20060101)G01N 21/95 (20060101) G01N 21/88 (20060101) AbstractA curved mirrored surface is used to collect radiation scattered by a sample surface and originating from a normal illumination beam and an oblique illumination beam. The collected radiation is focused to a detector. Scattered radiation originating from the normal and oblique illumination beams may be distinguished by employing radiation at two different wavelengths, by intentionally introducing an offset between the spots illuminated by the two beams or by switching the normal and oblique illumination beams on and off alternately. Beam position error caused by change in sample height may be corrected by detecting specular reflection of an oblique illumination beam and changing the direction of illumination in response thereto. Butterfly-shaped spatial filters may be used in conjunction with curved mirror radiation collectors to restrict detection to certain azimuthal angles.Other References
Field of SearchWith comparison to master, desired shape, or reference voltageINSPECTION OF FLAWS OR IMPURITIES Surface condition Detection of object or particle on surface On patterned or topographical surface (e.g., wafer, mask, circuit board) On patterned or topographical surface (e.g., wafer, mask, circuit board) Of surface reflection Transparent or translucent material Optical element (e.g., contact lens, prism, filter, lens, etc.) Patterned surface | |
