| 摘要 |
PROBLEM TO BE SOLVED: To prevent an object from being inclined by the force applied by the grinding when the object such as a wafer is ground by providing an actuator to incessantly change the edge pressure applicable to a chuck, and to change the relative direction of a drive structure to the chuck. SOLUTION: When a carrier head 200 is started to turn, a control system monitors the distance to be continuously measured by a sensor, compares the recorded reference distance with the measured value, and generates the appropriate pressure or the control signal to an actuator 215. The actuator 215 moves a carrier plate 230 relative to a drive plate 210 by applying the pressure necessary for keeping a wafer (and the drive plate 210) parallel to the surface to be ground. The torque prevents the wafer from being inclined relative to the surface to be ground by the friction on the surface of a grinding pad. |
