Patent ID: 7430986
Filing Date: 2008-10-07
Classification: H01J,Y10S

Abstract:
1. A plasma confinement ring assembly for a plasma processing chamber, comprising a plurality of vertically-stacked plasma confinement rings confining and surrounding a plasma space above a substrate support on which a semiconductor substrate is supported in the chamber, each of the plasma rings including an inner portion having a plasma-exposed inner diametric surface, an outer portion disposed radially outwardly from the inner portion, and at least one thermal choke adapted to reduce heat conduction from the inner portion to the outer portion when the inner diametric surface is exposed to plasma in the plasma processing chamber, such that the inner diametric surface reaches a sufficiently high temperature to substantially prevent polymer deposition thereon, wherein the at least one thermal choke comprises a plurality of circumferentially-extending slots which extend completely through the thickness of the plasma confinement ring, and each plasma confinement ring comprises through holes which are spaced radially outward from the slots.