| 摘要 |
<p>PURPOSE:To prevent an external force from being applied to a wafer so as to protect it against deformation by a method wherein the inner edge of a ring-shaped holding member protrudes inwards more than that of a ring-shaped pressing board, the periphery of a wafer is set smaller than the inner edge of the pressing board but larger than the inner edge of the holding member. CONSTITUTION:A ring-shaped holding pad 2 attracted to a stage 6 by vacuum suction, an elastic ring-shaped holding section 3 composed of an upper and a lower holder holding a wafer 1 between them on the holding pad 2, a ring- shaped pressing board 4 which holds the holding section 3 pressing it from above, and a bolt 5 which screws the pressing board 4 to the holding pad 2 are provided. The inner edge (3) of the holding section 3 protrudes inwards more than the inner edge (4) of the pressing board 4 and is adequate in size to hold the periphery of the wafer 1. The inner edge (4) of the pressing board 4 is located outside of the periphery of the wafer 1, so that the pressing board 4 is restrained from applying a compressive force directly to the wafer 1.</p> |
