| 摘要 |
The present invention provides a double-sided polishing method comprising a first polishing step in which polishing is performed at a high polishing rate, and a second polishing step in which polishing is then performed at a low polishing rate. The double-sided polishing method further comprises: a step in which, after polishing, a straight line that passes through the center of a wafer from the outermost periphery is divided into prescribed segments, and the cross-sectional shapes of the divided segments are optically measured; a step in which a predetermined weight is added to the measured cross-sectional shapes for each divided segment, and the flatness of each segment is quantified; and a step in which, on the basis of the quantified flatness, polishing conditions for the first polishing step and polishing conditions for the second polishing step are established for the next time polishing is performed. In the step for measuring the cross-sectional shapes, a light beam diameter of a measuring device used to measure the outermost segment that is smaller than a light beam diameter used to measure the segments other than the outermost segment is used. Thus, the double-sided polishing method enables the shape to the outermost periphery of the polished wafer to be measured with good precision, without lowering productivity, and enables the overall flatness of the wafer, including the outermost periphery of the wafer, to be improved. |
