Double-side polishing method

  • US 9,862,072 B2
  • Filed: 10/21/2013
  • Issued: 01/09/2018
  • Est. Priority Date: 11/13/2012
  • Status: Active Grant
First Claim
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1. A double-side polishing method comprising a polishing cycle that comprises:

  • performing a first polishing step of carrying out a double-side polishing process at a high polishing rate, the double-side polishing process simultaneously polishing both surfaces of a wafer that is held with a carrier and interposed between polishing pads each attached on upper and lower turn tables while rotating and revolving the carrier, supplying a polishing agent, and measuring a thickness of the wafer;

    performing a second polishing step of carrying out the double-side polishing process at a low polishing rate,dividing a straight line extending from one outermost circumference of the polished wafer through a center of the polished wafer to another outermost circumference into prescribed sections, and optically measuring a cross-sectional shape of the divided sections;

    applying a weight predetermined for each divided section to the measured cross-sectional shape to quantify flatness of each section; and

    determining polishing conditions of the first and second polishing steps in a subsequent polishing cycle on a basis of the quantified flatness, whereina beam diameter of a measurement apparatus used to measure the cross-sectional shape of outermost sections is smaller than that used to measure the cross-sectional shape of the other section.

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