Tightly fitted ceramic insulator on large area electrode

Abstract

Embodiments of the invention generally include shield frame assembly for use with a showerhead assembly, and a showerhead assembly having a shield frame assembly that includes an insulator that tightly fits around the perimeter of a showerhead in a vacuum processing chamber. In one embodiment, a showerhead assembly includes a gas distribution plate and a multi-piece frame assembly that circumscribes a perimeter edge of the gas distribution plate. The multi-piece frame assembly allows for expansion of the gas distribution plate without creating gaps which may lead to arcing. In other embodiments, the insulator is positioned to be have the electric fields concentrated at the perimeter of the gas distribution plate located therein, thereby reducing arcing potential.

Dependencies are inferred from the claim text.