Methods and apparatus for plasma liners with high fluid conductance

Abstract

Methods and apparatus for confining plasma in a process chamber. In some embodiments, the apparatus includes a first liner with a first set of openings, the first liner configured to surround a substrate support when installed and a second liner with a second set of openings, the second liner configured to surround the substrate support under the first liner when installed, wherein the first set of openings and the second set of openings are configured to be offset from each other when installed in the process chamber to prevent a line-of-sight through the first liner and the second liner from a top down viewpoint, and wherein the first liner and the second liner are configured to be spaced apart vertically when installed in the process chamber to allow high fluid conductance through the first set of openings and the second set of openings.

1 . An apparatus for confining plasma in a process chamber, comprising:
 a first liner with a first set of openings for fluid flow, the first liner configured to surround a substrate support of the process chamber when installed in the process chamber; and   a second liner with a second set of openings for fluid flow, the second liner configured to surround the substrate support of the process chamber under the first liner when installed in the process chamber,   wherein the first set of openings and the second set of openings are configured to be offset from each other when installed in the process chamber to prevent a line-of-sight through the first liner and the second liner from a top down viewpoint, and   wherein the first liner and the second liner are configured to be spaced apart vertically when installed in the process chamber to allow high fluid conductance through the first set of openings and the second set of openings.   
     
     
         2 . The apparatus of  claim 1 , wherein the first liner or the second liner is electrically conductive. 
     
     
         3 . The apparatus of  claim 2 , wherein the first liner or the second liner is formed form an aluminum based material. 
     
     
         4 . The apparatus of  claim 3 , wherein the first liner or the second liner is coated with a yttrium-based material. 
     
     
         5 . The apparatus of  claim 2 , wherein the first liner or the second liner is electrically grounded. 
     
     
         6 . The apparatus of  claim 5 , wherein the first liner or the second liner is configured to form a symmetrical radio frequency (RF) ground return path when installed in the process chamber. 
     
     
         7 . The apparatus of  claim 1 , wherein the first liner and the second liner are configured to be spaced apart vertically from approximately 0.25 inches to approximately 0.375 inches when installed in the process chamber. 
     
     
         8 . The apparatus of  claim 1 , wherein a vertical distance between the first liner and the second liner is configured to be adjustable when installed in the process chamber. 
     
     
         9 . The apparatus of  claim 1 , wherein a distance from a top surface of the first liner and a top surface of the substrate support is configured to be adjustable when the first liner is installed in the process chamber. 
     
     
         10 . The apparatus of  claim 1 , wherein the first set of openings or the second set of openings is configured in size to prevent parasitic plasma formation when the first liner or second liner is installed in the process chamber. 
     
     
         11 . The apparatus of  claim 1 , wherein the first liner has a first key for maintaining a first orientation when installed in the process chamber and the second liner has a second key for maintaining a second orientation when installed in the process chamber, wherein the first orientation of the first liner and the second orientation of the second liner yields an offset that provides no line-of-sight through the first liner and the second liner from a top down viewpoint when installed in the process chamber. 
     
     
         12 . The apparatus of  claim 1 , wherein the first liner and the second liner are ohmically connected via at least one conductive gasket. 
     
     
         13 . The apparatus of  claim 1 , wherein the first liner or second liner is circular in shape with an inner cutout, wherein the first set of openings or the second set of openings, respectively, extend radially outward from an inner edge near the inner cutout towards an outer edge of the first liner or the second liner, respectively. 
     
     
         14 . An apparatus for confining plasma in a process chamber, comprising:
 a first conductive liner with a first set of openings for fluid flow that is configured to surround a substrate support when installed in the process chamber, wherein the first set of openings are configured to be oriented with an offset relative to a second set of openings of a second conductive liner under the first conductive liner when installed in the process chamber.   
     
     
         15 . The apparatus of  claim 14 , wherein the first conductive liner is configured to be spaced apart from the second conductive liner when installed in the process chamber. 
     
     
         16 . The apparatus of  claim 14 , wherein the first conductive liner has a vertical inner periphery wall that is configured to be grounded to the substrate support when installed in the process chamber. 
     
     
         17 . The apparatus of  claim 14 , wherein the first conductive liner has a vertical outer periphery wall with an uppermost portion that is configured to make ohmic contact with a ground of the process chamber. 
     
     
         18 . An apparatus for confining plasma in a process chamber, comprising:
 a first conductive liner with a first set of openings for fluid flow that is configured to surround a substrate support when installed in the process chamber, wherein the first set of openings are configured to be oriented with an offset relative to a second set of openings of a second conductive liner above the first conductive liner when installed in the process chamber.   
     
     
         19 . The apparatus of  claim 18 , wherein the first conductive liner is configured to be spaced apart from the second conductive liner when installed in the process chamber. 
     
     
         20 . The apparatus of  claim 18 , wherein the first conductive liner has a top inner periphery edge portion that is configured to make ohmic contact with a bottom inner periphery edge portion of the second conductive liner and a top outer periphery edge portion that is configured to make ohmic contact with a bottom outer periphery edge portion of the second conductive liner when installed in the process chamber.