Multi-layer ceramic electrostatic chuck with integrated channel

A semiconductor wafer support chuck having small diameter gas distribution ports for heat transfer gas. The diameter ports inhibit plasma ignition in heat transfer gas distribution channels. The ports are less than 20 mils in diameter less than 3 mm in length. The short length of the ports facilitates fabrication of multiple ports of very small diameter. The ports communicate with a gas distribution plenum integrated into the body of the chuck beneath a wafer support surface. The plenum has radial channels and a peripheral groove for distributing heat transfer gas to the wafer support surface.