Patent ID: 7713390

Claim:
Apparatus for processing a substrate disposed in a physical vapor deposition chamber having a target disposed in a lid assembly and a grounded chamber wall comprising: a ground frame configured to be insulatively coupled to the lid assembly, the ground frame having an electrically conductive lower surface; and a ground shield having an electrically conductive wall adjustably and electrically coupled to the conductive lower surface of the ground frame, the ground shield having a plurality of segments independently adjustable with respect to the ground frame, the ground shield configured to circumscribe the target and having an upper edge disposed proximate and substantially parallel to a protruding edge of the target to form a gap therebetween which is narrow enough to prevent the glow discharge of a plasma from entering the gap when installed, wherein the direction of the gap is substantially perpendicular to or at an angle to the target, and the ground shield is substantially perpendicular to a surface of the target facing the substrate or at an angle either towards or away from a central axis of the chamber.