Patent ID: 7254900

Claim:
A wafer handling apparatus for handling a semiconductor wafer, said wafer handling apparatus comprising: a plurality of edge wheels arranged for rotatably supporting the wafer, each of the edge wheels comprising a wheel body having a groove formed in an outer periphery of said wheel body, said groove being configured to engage an edge of said wafer such that the wafer may be inserted into the groove and supported by the groove, each of the edge wheels having an axis upon which the edge wheel is configured to rotate, wherein at least one of the edge wheels has a radial channel extending into the wheel body from said groove and a through-hole formed along the axis of the at least one edge wheel; a shaft extending through said through-hole, the shaft supporting the wheel body for rotation about the shaft, said radial channel being in at least periodic fluid communication with a stationary port on one of said edge wheel and said shaft as said edge wheel rotates on said shaft.