| 摘要 |
PROBLEM TO BE SOLVED: To carry out the centering of a wafer surely, rapidly and precisely by enabling the centering of the wafer on a wafer holding device holding the wafer rotatively. SOLUTION: The device has a wafer chuck; a wafer mounting board 4 with a wafer receiving hole 5 for mounting the wafer concentrically with the wafer chuck; at least three groups of centering units which are provided on the wafer mounting board and provided at regular intervals along the wafer receiving hole, and press the wafer to a central direction; and a centering driving mechanism for carrying out centering by driving the centering units synchronously. The centering unit has a piston 18 which moves back and forth in the radial direction of the wafer receiving hole and can be brought into contact with a wafer circumferential edge. The centering driving mechanism moves the piston back and forth. The wafer chuck and the wafer mounting board can relatively move up and down. COPYRIGHT: (C)2004,JPO |
