| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve accurate calibration of encoder stage position measurement. <P>SOLUTION: In a calibration method to calibrate an encoder position measurement system of a stage, the encoder position measurement system includes an encoder grid and at least two sensor heads cooperating with the encoder grid, each sensor head providing a sensor head output signal showing position sensitivity in a horizontal and a vertical direction, and the method includes: (a) moving the stage such that the sensor heads are moved with respect to the encoder grid, or vice versa; (b) during the moving, measuring the position of the stage with respect to the encoder grid by the two sensor heads; (c) determining a vertical position data map from the sensor head output signals of the two sensor heads; (d) calculating a horizontal position data map from the vertical position data map; and (e) calibrating the encoder position measurement system by using the calculated horizontal position data map. <P>COPYRIGHT: (C)2010,JPO&INPIT |
