Compound clamp ring for semiconductor wafers

摘要

A compound clamp ring secures a semiconductor wafer having a wafer flat portion to a wafer pedestal during wafer processing while maintaining a continuous seal between the wafer edges and the wafer pedestal to prevent leakage of coolant gases circulated at the backside of the wafer into the process environment. The clamp ring has an annular wafer clamp surface adapted to press a round portion of the wafer into sealing abutment with the wafer pedestal. A cavity formed in the clamp ring securely receives a comb-like array of resilient flexures that are adapted to apply a yieldable bias to the flat portion of the wafer to complete the seal between the wafer and the pedestal at the flat portion of the wafer; and encloses the flexures to shield the flexures from process gases.