Apparatus for transporting an electrically conductive wafer

Abstract

A wafer transporter comprising a plurality of plane electrodes which are horizontally coplanar with each other. The plane electrodes face the wafer to be transported. A plurality of air nozzles are provided through the electrodes, and air is blown from the nozzles perpendicularly toward the wafer surface. A voltage is applied between the electrodes facing the wafer. The applied voltage is divided by the capacitances between the wafer which is electrically conductive, and the electrodes, thus the wafer is attracted vertically toward the electrode, and is maintained without friction by the balance of the repulsive force of the air blowing and the attractive electrostatic force. The divided voltages become unequal due to the difference of the wafer area facing respective electrodes. This voltage difference produces a horizontal force which moves the wafer in a horizontal direction. The wafer is forced to stay at a balancing point where the induced voltages are equal. This is used to prevent the wafer from deviating from the course. Successive switching of the applied voltage to a next electrode in the direction of the wafer's movement allows the wafer to travel along the row of the electrodes.