PURPOSE: To certainly secure a plane surface holding a wafer by dint of suction force as well as to make a back cover detachable, by forming the back cover into an extremely pliable structure as compared with a suction surface constituent member, in case of a vacuum chuck for wafer suction use.
CONSTITUTION: A back cover 12 is detachably installed on the backside of a suction block 11. A central part 18 of the back cover 12 consists of an extremely pliable structure as compared with a suction surface constituent member 11". The degree of the pliability is as follows that the back cover 12 is deformed by receiving bending force by the atmospheric pressure at exhaustion in exhaust spaces 14 and 15, and the bending force is made to oppose another bending force that a suction surface 11' being in the opposite direction receives by the atmospheric pressure through contact with the backside of the suction surface 11', thereby making the amount of deformation in the suction surface 11' extremely reducible. When the exhaust of these exhaust spaces 14 and 15 takes place in order to attract a wafer, the back cover 12 is also deformed by receiving the bending force by the atmospheric pressure, so that the suction surface keeps its highly accurate flatness.
KAWAMURA YOSHIO
YAMAGUCHI SUMIO
MATSUMURA YASUHIDE
NAKAZAWA HIDEO
KAWAGUCHI KOUJI
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