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Particle analysis of notched wafers

  • US 5,381,004 A
  • Filed: 08/31/1993
  • Issued: 01/10/1995
  • Est. Priority Date: 08/31/1993
  • Status: Expired due to Term
First Claim
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1. A method for locating particles on a notched semiconductor wafer, the method comprising:

  • (a) scanning a notched semiconductor wafer with a scanning device to obtain scanning device coordinates pertaining to the positions of;

    (i) the center of the wafer, (ii) the wafer notch, and (iii) contaminant particles on the wafer;

    (b) finding the wafer notch with an imaging device and obtaining its estimated imaging device coordinates;

    (c) finding the wafer center with an imaging device and obtaining its estimated imaging device coordinates;

    (d) calculating estimated transformation parameters for a coordinate transformation between the coordinate systems of the scanning device and the imaging device based on the scanning device coordinates and the estimated imaging device coordinates of the wafer notch and the wafer center; and

    (e) transforming the scanning device coordinates of the particles on the wafer to estimated imaging device coordinates using the estimated transformation parameters.

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