| 摘要 |
A method for calibrating alignment of an end effector with respect to a chuck in a plasma processing system is disclosed. The method includes providing a first light beam from the end effector to said chuck, moving the end effector along a predefined calibration path such that the first light beam traverses a surface of the chuck, receiving a set of reflected light signals being generated at least when the surface reflects the first light beam during the moving, and analyzing the set of reflected light signals to identify three or more discontinuities, generated when the first light beam encounters an edge of the chuck. The method also includes determining three or more coordinate data points representing three or more points on the edge of the chuck, and determining a center of the chuck based on the three or more coordinate data points. |
