Patent ID: 8308896

Claim:
A method of cleaning a bevel edge of a substrate in a processing chamber, comprising: placing a substrate on a substrate support in said processing chamber; flowing a cleaning gas through a gas feed located near a center of a gas distribution plate opposing said substrate support, and disposed at a distance from said substrate support; and generating a cleaning plasma near said bevel edge of said substrate to clean said bevel edge by powering an edge electrode, said edge electrode being one of a bottom edge electrode and a top edge electrode, with a RF power source and grounding said edge electrode that is not powered by said RF power source, said bottom edge electrode surrounds said substrate support and said top edge electrode surrounds said gas distribution plate, wherein said bottom edge electrode has at least a portion of a top surface at the same level as a top surface of said substrate support, wherein there is provided a bottom dielectric ring being disposed between said bottom edge electrode and said substrate support, wherein said bottom dielectric ring is in surrounding relationship with said substrate support, said bottom dielectric ring electrically separating said substrate support and said bottom edge electrode; further wherein said gas distribution plate is provided with at least a gas feed for supplying a gas; further wherein there is provided a top dielectric ring surrounding said gas distribution plate, wherein said top edge electrode surrounds said gas distribution plate opposing said substrate support, wherein said top dielectric ring is disposed between said top edge electrode and said gas distribution plate, and said top edge electrode and said gas distribution plate are electrically isolated from each other by said top dielectric ring; and wherein there is further provided a bottom insulating ring surrounding and coupled to said bottom edge electrode, wherein said bottom edge electrode is disposed between said bottom insulating ring and said bottom dielectric ring, and wherein an inner portion of said bottom insulating ring is taller than an outer portion of said bottom insulating ring, said inner portion of said bottom insulating ring being disposed closer to said bottom edge electrode than said outer portion of said bottom insulating ring.