Tuned potential pedestal for mask etch processing apparatus

Abstract

The present invention generally provides an improved pedestal for supporting a substrate. The pedestal has greatest application during a plasma etching process, such as for a quartz photomask, or “reticle.” The pedestal defines a body, and a substrate support base along an upper surface of the body. The substrate support base has an outer edge, and an intermediate substrate support ridge for receiving and supporting the substrate. At least a portion of the substrate support base outside of the intermediate substrate support ridge is fabricated from a dielectric material. The purpose is to couple greater RF power through the reticle in order to enhance the plasma etching process.

1 . A pedestal for supporting a substrate in a plasma etching chamber, comprising: 
 a body, the body being configured to receive an RF power; and    a substrate support base along an upper surface of the body, the substrate support base having an outer edge, and an intermediate substrate support ridge for receiving and supporting the substrate;    and wherein at least a portion of the substrate support base outside of the intermediate substrate support ridge is fabricated from a dielectric material.    
   
   
       2 . The pedestal of  claim 1 , wherein the portion of the substrate support base within the substrate support ridge is fabricated from a metallic material.  
   
   
       3 . The pedestal of  claim 2 , wherein the portion of the substrate support base fabricated from a dielectric material is formed by placing a layer of dielectric material along a top surface of the substrate support base outside of the substrate support ridge in order to form a dielectric ring.  
   
   
       4 . The pedestal of  claim 3 , wherein the substrate support ridge is fabricated from a metallic material.  
   
   
       5 . The pedestal of  claim 3 , wherein the dielectric material is fabricated from materials selected from the group consisting of a polymeric material, a ceramic material, and combinations thereof.  
   
   
       6 . The pedestal of  claim 2 , wherein the portion of the substrate support base fabricated from a dielectric material defines substantially the entire thickness of the substrate support base outside of the substrate support ridge.  
   
   
       7 . The pedestal of  claim 6 , wherein the substrate support ridge is fabricated from a metallic material.  
   
   
       8 . The pedestal of  claim 6 , wherein the dielectric material is fabricated from materials selected from the group consisting of a polymeric material, a ceramic material, and combinations thereof.  
   
   
       9 . The pedestal of  claim 1 , further comprising a cover configured to be received on the substrate support base.  
   
   
       10 . A pedestal for supporting a reticle in a plasma etching chamber, comprising: 
 a body, the body being configured to receive an RF power;    a reticle support base along an upper surface of the body, the reticle support base having an outer edge, and an intermediate reticle support ridge for receiving and supporting the reticle;    and wherein at least a portion of the reticle support base outside of the intermediate substrate support ridge is fabricated from a dielectric material.    
   
   
       11 . The pedestal of  claim 10 , wherein: 
 the portion of the reticle support base within the reticle support ridge is fabricated from a metallic material;    the reticle support ridge is fabricated from a metallic material; and    
   
   
       12 . The pedestal of  claim 10 , wherein the dielectric material is fabricated from at least one of a polymeric material and a ceramic material.  
   
   
       13 . The pedestal of  claim 12 , wherein the portion of the reticle support base fabricated from a dielectric material is formed by placing a layer of dielectric material along a top surface of the reticle support base outside of the reticle support ridge in order to form a dielectric ring.  
   
   
       14 . The pedestal of  claim 12 , wherein the portion of the reticle support base fabricated from a dielectric material defines substantially the entire thickness of the reticle support base outside of the reticle support ridge  
   
   
       15 . A plasma etching chamber having a pedestal therein for supporting a reticle, comprising: 
 a chamber body defining a base wall, a side wall and a dome;    a gate along the side wall for permitting a reticle to be moved into the plasma etching chamber; and    a reticle support member for supporting a reticle within the plasma etching chamber during processing, the reticle support member comprising: 
 a body, the body being configured to receive an RF power;  
 a reticle support base along an upper surface of the body, the reticle support base having an outer edge, and an intermediate reticle support ridge for receiving and supporting the reticle;  
 and wherein at least a portion of the reticle support base outside of the intermediate substrate support ridge is fabricated from a dielectric material.  
   
   
   
       16 . The chamber of  claim 15 , wherein: 
 the portion of the reticle support base within the reticle support ridge is fabricated from a metallic material;    the reticle support ridge is fabricated from a metallic material; and    
   
   
       17 . The chamber of  claim 16 , wherein the dielectric material is fabricated from at least one of a polymeric material and a ceramic material.  
   
   
       18 . The chamber of  claim 17 , wherein the portion of the reticle support base fabricated from a dielectric material is formed by placing a layer of dielectric material along a top surface of the reticle support base outside of the reticle support ridge in order to form a dielectric ring.  
   
   
       19 . The chamber of  claim 17 , wherein the portion of the reticle support base fabricated from a dielectric material defines substantially the entire thickness of the reticle support base outside of the reticle support ridge