Patent ID: 7147749

Claim:
An upper electrode assembly for a plasma processing system, comprising: an electrode plate comprising a first surface for coupling said upper electrode to an upper assembly, a second surface comprising a plasma surface and a mating surface for mating said electrode plate with said plasma processing system, a peripheral edge, and a plurality of gas injection orifices coupled to said first surface and said second surface; a deposition shield attached said electrode plate, said deposition shield comprising a cylindrical wall having an inner surface contiguous with said plasma surface, an outer surface contiguous with said mating surface, and a distal end surface, wherein said distal end surface comprises: a distal end mating surface extending radially inward from said outer surface, and a protrusion adjacent to said inner surface and protruding from said distal end mating surface, said protrusion having a distal end lip surface thereon; and a protective barrier provided on exposed surfaces of said upper electrode assembly, said exposed surfaces comprising said plasma surface, said inner surface, and said distal end lip surface.