POROUS CHUCK HAVING MULTIPLE POROUS PLATE

摘要

The present invention relates to a porous chuck having multiple absorption plates for absorbing a wafer using vacuum suction force to be fixed. The porous chuck having multiple absorption plates according to the present invention comprises a base having a vacuum supply hole formed at the center to apply the vacuum suction force; and multiple absorption plates mounted on the base, having multiple blow holes inside, capable of forming the vacuum suction force on the surface by dispersing the vacuum suction force applied through the vacuum supply hole to the surface through the blow holes, and having each different mesh size. Vacuum dispersing paths for dispersing the vacuum suction force applied to the vacuum supply hole are formed between the base and the multiple absorption plates. One among the multiple absorption plates is arranged to surround another absorption plate. One absorption plate radially arranged farther toward outer side than another absorption plate has the larger mesh size.