Defect detection system
April 6, 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 ReferencesDefect detection system Scanning contaminant and defect detector Method for determining the quality of light scattering material Method and apparatus for inspecting specimen surface Reflection densitometer with ellipsoid reflection surface System for checking defects on a flat surface of an object Radiant energy reradiating flow cell system and method Method for determining the phase of phase transformable light scattering material Apparatus and method for detecting defects and dust on a patterned surface Method and apparatus for determining the volume & index of refraction of particles InventorsAssigneeApplicationNo. 828269 filed on 04/06/2001US Classes:356/237.2, Surface condition356/237.4, 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: Font, Frank G.Assistant: Nguyen, Son T. Attorney, Agent or FirmForeign Patent References
International ClassesG01N 021/00337-339 AbstractScattered radiation from a sample surface is collected by means of a collector that collects radiation substantially symmetrically about a line normal to the surface. The collected radiation is directed to channels at different azimuthal angles so that information related to relative azimuthal positions of the collected scattered radiation about the line is preserved. The collected radiation is converted into respective signals representative of radiation scattered at different azimuthal angles about the line. The presence and/or characteristics of anomalies are determined from the signals. Alternatively, the radiation collected by the collector may be filtered by means of a spatial filter having an annular gap of an angle related to the angular separation of expected pattern scattering. Signals obtained from the narrow and wide collection channels may be compared to distinguish between micro-scratches and particles. Forward scattered radiation may be collected from other radiation and compared to distinguish between micro-scratches and particles. Intensity of scattering is measured when the surface is illuminated sequentially by S- and P-polarized radiation and compared to distinguish between micro-scratches and particles. Representative films may be measured using profilometers or scanning probe microscopes to determine their roughness and by the above-described instruments to determine haze in order to build a database. Surface roughness of unknown films may then be determined by measuring haze values and from the database.Other References
Field of SearchINSPECTION OF FLAWS OR IMPURITIESSurface 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) Having predetermined light transmission regions (e.g., holes, aperture, multiple material articles) Transparent or translucent material Patterned surface Surface condition Detection of an object or particle on surface OF LIGHT REFLECTION (E.G., GLASS) SURFACE ROUGHNESS POSITION OR DISPLACEMENT | |
