Apparatus and method for detecting wafer position

摘要

Apparatus and method for detecting wafer position is described. The apparatus for detecting wafer position includes a first sensor group and a second sensor group. The first sensor group and the second sensor group both include at least one light emitter and at least one light receiver. In one case, the light emitter is at one side beside a wafer and the light receiver is at the same height with the light emitter at the opposing side beside the wafer. In the other case, the light emitter neighbors the light receiver vertically at the same side beside the wafer. When the apparatus for detecting wafer position is operating, the apparatus determines whether a wafer position is normal by the relative position between the wafer and the sensors (the first sensor group and the second sensor group). Once the wafer position is abnormal and the time interval between the trigger of the first sensor group and the trigger of the second sensor group deviates the predetermined time interval the apparatus for detecting wafer position reports the abnormal event to the equipment including the apparatus to stop the motion of the wafer lifter and the motion of the robot blade in the process chamber. At the same time, the equipment including the apparatus for detecting wafer position alarms people in the production to proceed with troubleshooting.