Patent ID: 6869266

Claim:
An apparatus for supporting a wafer in a wafer handling device, the wafer having an annular exclusion area extending a predetermined distance radially inward from a peripheral rim of the wafer, and the wafer handling device having a selectively operable vacuum source, the apparatus comprising: a body member having an outer peripheral edge, a wafer-support surface including an annular rim extending about said outer peripheral edge, and an internal vacuum plenum, said wafer-support surface including a plurality of vacuum ports arranged in a mutually spaced relationship so as to underlie the annular exclusion area of the wafer when the wafer is positioned thereat, the vacuum plenum communicating with the vacuum source for evacuating air therefrom to thereby apply a subatmospheric pressure thereto; and a plurality of flow diverters positioned within said vacuum plenum and partitioning said vacuum plenum into a plurality of vacuum distribution channels, at least one of said plurality of vacuum distribution channels being in fluid communication with at least one of said plurality of vacuum ports, said flow diverters redirecting the subatmospheric pressure among said plurality of vacuum distribution channels as each of said plurality of vacuum ports is occluded by a portion of the wafers, wherein said body member further comprises a wall dividing said internal vacuum plenum into two portions, each of said portions including at least one of said plurality of flow diverters, and each of said portions coupled separately by one of a pair of vacuum ducts with a common passageway communicating with the vacuum source.