Patents by Inventor Wo-Tak Wu

Wo-Tak Wu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7755042
    Abstract: A scanning electron beam apparatus with an Auger spectrometer. The apparatus includes at least an electron column for generating a primary electron beam, a magnetic objective lens configured to focus the primary electron beam onto a surface of a target substrate, and a spectrometer configured to detect Auger electrons emitted from the surface of the target substrate. The magnetic objective lens applies a magnetic field strength greater than 10 Gauss and less than 50 Gauss at the surface of the target substrate. Other embodiments, aspects and features are also disclosed.
    Type: Grant
    Filed: May 21, 2008
    Date of Patent: July 13, 2010
    Assignee: KLA-Tencor Corporation
    Inventors: Gabor D. Toth, Rudy F. Garcia, Chris Huang, Niles Kenneth MacDonald, Mehran Nasser-Ghodsi, Garrett Pickard, Khashayar Shadman, Wo-Tak Wu, Ming Yu
  • Patent number: 6097428
    Abstract: A method and apparatus for inspecting the surface of an object such as a semiconductor wafer for contaminant particles. The apparatus includes a light source for illuminating an area on the surface of the object. A camera is positioned above the surface of the object and detects light scattered by any particles present on the surface at that area, the camera detecting light scattered from the area over a field of view, or window, which is defined by the camera, a focusing lens and the relative distance therebetween. A computer is coupled to the camera and serves to store, process, identify and/or analyze the light detected by the camera. The computer also serves to calculate a minimum light intensity threshold level which is dynamic to compensate for variances in the background light intensity of different portions of the object. The value of the threshold level is calculated for each window of the object defined by the apparatus using the equation: T.sub.W =.mu..sub.W +.eta.-.delta..sub.W, where T.sub.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: August 1, 2000
    Assignee: Inspex, Inc.
    Inventors: Wo-Tak Wu, Shun-Tak Wu, Joe Danko, Roy Foster