Patent ID: 8187413

Claim:
An electrode assembly comprising a thermal control plate, a silicon-based showerhead electrode, and a thermally conductive gasket, wherein: the thermal control plate comprises a frontside and a plurality of process gas passages; the showerhead electrode comprises a backside, a first showerhead passage, and a second showerhead passage; the thermal control plate and the showerhead electrode are engaged such that the frontside of the thermal control plate faces the backside of the showerhead electrode; the process gas passages of the thermal control plate, the first showerhead passage of the showerhead electrode, and the second showerhead passage of the showerhead electrode cooperate to permit passage of a process gas through the electrode assembly; and the respective profiles of the frontside of the thermal control plate and the backside of the showerhead electrode each cooperate to define a disjointed thermal interface, wherein: the frontside of the thermal control plate comprises a first frontside proximal portion that terminates at the first showerhead passage of the showerhead electrode, a second frontside proximal portion that terminates at the second showerhead passage of the showerhead electrode, and a frontside displaced portion that is offset relative to the first frontside proximal portion and the second frontside proximal portion of the frontside of the thermal control plate; the frontside displaced portion of the frontside of the thermal control plate is separated from the first showerhead passage of the showerhead electrode by the first frontside proximal portion of the frontside of the thermal control plate; the backside of the showerhead electrode comprises a first backside proximal portion that terminates at the first showerhead passage of the showerhead electrode, a second backside proximal portion that terminates at the second showerhead passage of the showerhead electrode, and a backside displaced portion that is offset relative to the first backside proximal portion and the second backside proximal portion of the backside of the showerhead electrode; the backside displaced portion of the backside of the showerhead electrode is separated from the first showerhead passage of the showerhead electrode by the first backside proximal portion of the backside of the showerhead electrode; and the thermally conductive gasket is positioned along the frontside displaced portion of the frontside of the thermal control plate and the backside displaced portion of the backside of the showerhead electrode such that the thermally conductive gasket is isolated from the first showerhead passage of the showerhead electrode.