Patent ID: 8202140

Claim:
A wafer polishing carrier apparatus, comprising: a drive rotary union configured to rotate on a given axis and to receive a flow of fluid through a first conduit in a sealed-up state thereof; driven rotary unions configured to revolve on their own axis at different sides of the drive rotary union, and to receive the flow of the fluid from the drive rotary union through a second conduit in a sealed-up state thereof; carriers, each carrier attached to an end part of a different one of the driven rotary unions to adsorb or detach a wafer by using a pressure from the flow of the fluid provided through a third conduit connected to the second conduit of the corresponding driven rotary union; and a filter configured to filter pollution material contained in the flow of the fluid as it flows in and out of the third conduit on a periphery of each carrier to prevent the pollution material from escaping external to each carrier, the pollution material being generated from a rotation of the drive rotary union and the driven rotary union.