| 摘要 |
A method and apparatus for finding wafer index marks and centers. A wafer having a flat or notch along its edge is placed on a rotatable platform so that a portion of the wafer's edge is positioned within a sensor assembly. The wafer is rotated, and the sensor reads the distance from the center of rotation to the edge of the wafer. This distance is measured at several angles of the wafer and the data is stored in a digital computer as a series of datapoints including an angle and a distance. A computer-implemented process calculates various geometries concerning the wafer including the location of the index mark and the center of the wafer.
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