| 摘要 |
PURPOSE:To closely contact the entire suface of a wafer with a mask by projecting a plurality of pins disposed on the same plane from the wafer adhering surface of a chuck body. CONSTITUTION:A wafer 2 is fixed by attracting of a hole 6 on the attracting surface 3a of a cuck body 3, and positioned with a mask 1. The body 3 is raised to lightly contact the wafer with the mask, a space 11 is sucked from a hole 12 to raise a supporting plate 9, a pin 10 is projected, and the suction of the hole 8 is stopped. Since the upper end of the pin is disposed on the plane, and the upper end of the pin is contacted only with the raised part of the wafer directed downward. When the wafer is raised upward, the sealability with the mask of the wafer is good. Accordingly, it is not particularly necessary to lift the pin. Thus, the strain of the wafer is corrected and the wafer is contacted preferably with the entire surface of the mask. According to this structure, the improper contact due to the warpage of the wafer and the improper contact due to dusts 5 between the back surface of the wafer and the chuck body can be prevented. |
