Patent ID: 8083890

Claim:
A plasma etching processing chamber configured to etch a thin film on a bevel edge of a substrate, comprising: a bottom edge electrode surrounding a substrate support in the plasma processing chamber, wherein the substrate support is configured to receive the substrate and the bottom edge electrode and the substrate support are electrically isolated from each other by a bottom dielectric ring, the bottom dielectric ring having a raised portion closer to a surface of the substrate support and a lowered potion near the bottom edge electrode; a top edge electrode surrounding a gas distribution plate opposing the substrate support, wherein the top edge electrode and the gas distribution plate are electrically isolated from each other by a top dielectric ring, and the top edge electrode and the bottom edge electrode are configured to generate an etching plasma near the bevel edge to remove the thin film on the bevel edge of the substrate, wherein the distance between the top edge electrode and the bottom edge electrode is less than about 1.5 cm to confine the etching plasma; a center gas feed embedded in the gas distribution plate, wherein the center gas feed is configured to deliver either an etching process gas or a tuning gas into the plasma processing chamber through the center gas feed; a center gas selection controller coupled to a center gas manifold, and wherein the center gas selection controller is coupled to the center gas feed and selects the etching process gas or the tuning gas delivery into the plasma processing chamber; an edge gas feed configured to deliver either the etching process gas or the tuning gas toward the bevel edge of the substrate, wherein the edge gas feed is disposed above the substrate; and an edge gas selection controller coupled to an edge gas manifold, and wherein the edge gas selection controller is coupled to edge gas feed and selects the etching process gas or the tuning gas delivery into the plasma processing chamber through the edge gas feed.