Plasma reaction chamber and captive silicon electrode plate for processing semiconductor wafers

Abstract

A plasma processing system for etching a semiconductor wafer comprises: 1) a plasma chamber in which the semiconductor wafer may be mounted; 2) an upper ring capable of being mounted on an upper opening of the plasma chamber, wherein a central portion of the upper ring forms a hole; and 3) an electrode plate having a plurality of vias therethrough. The electrode plate is disposed in the hole in the upper ring, wherein the central portion of the upper ring further forms a shelf for supporting the electrode plate in the hole.

1 . A plasma processing system for etching a semiconductor wafer comprising: 
 a plasma chamber in which said semiconductor wafer may be mounted;    an upper ring capable of being mounted on an upper opening of said plasma chamber, wherein a central portion of said upper ring forms a hole; and    an electrode plate having a plurality of vias therethrough, wherein said electrode plate is disposed in said hole in said upper ring, wherein said central portion of said upper ring further forms a shelf for supporting said electrode plate in said hole.    
   
   
       2 . The plasma processing system as set forth in  claim 1 , wherein said shelf is formed on an interior side in said hole in said upper ring.  
   
   
       3 . The plasma processing system as set forth in  claim 2 , wherein said shelf encircles said hole and projects inward towards a center of said hole.  
   
   
       4 . The plasma processing system as set forth in  claim 3 , wherein said shelf has an upper surface capable of supporting a perimeter region of a lower surface of said electrode plate when said electrode plate is inserted into said hole.  
   
   
       5 . The plasma processing system as set forth in  claim 4 , further comprising a retaining ring disposed on an upper surface of said upper ring, wherein said retaining ring encircles and overlaps said hole and holds said electrode plate in place in said hole.  
   
   
       6 . The plasma processing system as set forth in  claim 5 , wherein said retaining ring is made of aluminum.  
   
   
       7 . The plasma processing system as set forth in  claim 5 , wherein said electrode plate is made of a semiconductor material.  
   
   
       8 . The plasma processing system as set forth in  claim 5 , further comprising an O-ring capable of forming a gas-tight seal between said retaining ring and said electrode plate.  
   
   
       9 . The plasma processing system as set forth in  claim 8 , wherein said O-ring is disposed in a groove formed in said retaining ring.  
   
   
       10 . The plasma processing system as set forth in  claim 8 , wherein said O-ring is disposed in a groove formed in said electrode plate.  
   
   
       11 . The plasma processing system as set forth in  claim 5 , wherein said electrode plate and said hole in said upper ring are circular.