APPARATUS OF SUPPORTING A WAFER HAVING KNIFE EDGE RING

摘要

A wafer supporting apparatus having a knife edge ring is provided to maintain the fastening force of a level adjusting bolt for adjusting a level of the knife edge ring which is positioned on an inner cup. A wafer(21) is loaded on a chuck(23), and a sidewall of the chuck is surrounded by an inner cup(31). A knife edge ring(33) is disposed on an upper portion of the inner cup to surround the sidewall of the chuck, and has a first through-hole(33a). A first level adjusting bolt is fastened to the first through-hole, and an end portion of the first level adjusting bolt contacts the upper surface of the inner cup. A second level adjusting bolt is fastened to the first through-hole, and is positioned on the first level adjust bolt.