Ground path systems for providing a shorter and symmetrical ground path

Abstract

Embodiments described herein relate to ground path systems providing a shorter and symmetrical path for radio frequency (RF) energy to propagate to a ground to reduce generation of the parasitic plasma. The ground path system bifurcates the processing volume of the chamber to form an inner volume that isolates an outer volume of the processing volume.

What is claimed is: 
     
         1 . A chamber suitable for processing semiconductor substrates, comprising:
 a chamber body;   a chamber lid coupled to the chamber body to define a process volume;   a faceplate coupled to the chamber lid;   a pedestal disposed in the processing volume a pumping plate disposed concentric to the pedestal in the processing volume;   a ground bowl positioned in the processing volume, the ground bowl coupled to a lift system that moves the ground bowl between an elevated processing position and a lowered processing position; and   a ground bowl conductor coupled to the ground bowl, the ground bowl conductor contacting the pumping plate when the ground bowl is in the elevated processing position.   
     
     
         2 . The chamber of  claim 1 , wherein the pedestal is coupled to a stem, the stem disposed through an opening of the chamber. 
     
     
         3 . The chamber of  claim 2 , further comprising a radio frequency (RF) source coupled to an electrode disposed within the pedestal through a RF matching circuit electrically coupled to the electrode by a conductive rod disposed through the stem. 
     
     
         4 . The chamber of  claim 3 , wherein the ground bowl conductor is in a compressed state when the ground bowl is in the elevated processing position, the compressed state forming a primary RF cage for RF energy. 
     
     
         5 . The chamber of  claim 4 , wherein the ground bowl conductor includes a plurality of bellows. 
     
     
         6 . The chamber of  claim 5 , wherein the ground bowl conductor is spaced from the pumping plate in the lowered processing position. 
     
     
         7 . The chamber of  claim 1 , further comprising a plurality of lift pins disposed through the pedestal, wherein the ground bowl conductor surrounds the plurality of lift pins. 
     
     
         8 . A chamber suitable for processing semiconductor substrates, comprising:
 a chamber body;   a chamber lid coupled to the chamber body to define a process volume;   a faceplate coupled to the chamber lid;   a pedestal disposed in the processing volume;   a pumping plate disposed concentric to the pedestal in the processing volume;   a ground bowl positioned in the processing volume, the ground bowl coupled to a lift system that moves the ground bowl between an elevated processing position and a lowered processing position; and   a ground bowl conductor coupled to the ground bowl, the ground bow conductor comprising at least one of aluminum, a nickel-based alloy, and stainless steel, the ground bowl conductor contacting the pumping plate when the ground bowl is in the elevated processing position.   
     
     
         9 . The chamber of  claim 8 , wherein the ground bowl conductor is aluminum. 
     
     
         10 . The chamber of  claim 8 , wherein the ground bowl conductor is stainless steel. 
     
     
         11 . The chamber of  claim 8 , wherein the ground bowl conductor is the nickel-based alloy. 
     
     
         12 . The chamber of  claim 7 , wherein the ground bowl conductor includes a plurality of bellows. 
     
     
         13 . The chamber of  claim 8 , wherein the process volume has a first surface area when the ground bowl is in the elevated processing position and a second surface area when the ground bowl is in the lowered processing position, and the first surface area is less than the second surface area. 
     
     
         14 . A chamber suitable for processing semiconductor substrates, comprising:
 a chamber body;   a chamber lid coupled to the chamber body to define a process volume, the chamber lid including a faceplate coupled thereto;   a faceplate coupled to the chamber lid;   a pedestal disposed in the processing volume, the pedestal coupled to a stem extending out of the chamber body;   a pumping plate disposed radially outward of the pedestal;   a ground bowl coupled to a lift system that moves the ground bowl between an elevated processing position and a lowered processing position; and   a ground bowl conductor coupled to the ground bowl, the ground bowl conductor contacting the pumping plate when the ground bowl is in the elevated processing position and spaced from the pumping plate when the ground bowl is in the lowered processing position, wherein the process volume has a first surface area when the ground bowl is in the elevated processing position and a second surface area when the ground bowl is in the lowered processing position, and the first surface area is less than the second surface area.   
     
     
         15 . The chamber of  claim 14 , wherein the ground bowl conductor includes a plurality of bellows. 
     
     
         16 . The chamber of  claim 15 , wherein the bellows are compressed when the ground bowl is in the elevated processing position. 
     
     
         17 . The chamber of  claim 16 , wherein the ground bowl comprises aluminum. 
     
     
         18 . The chamber of  claim 17 , wherein the ground bowl conductor comprises stainless steel. 
     
     
         19 . The chamber of  claim 16 , wherein the ground bowl comprises stainless steel. 
     
     
         20 . The chamber of  claim 19 , wherein the ground bowl conductor comprises stainless steel.