Silicon carbide focus ring for plasma etching system

Abstract

A high resistivity silicon carbide focus ring for use in a plasma etching system is described. The focus ring comprises an upper surface, a lower surface, an inner radial edge, and an outer radial edge, and is configured to surround a substrate on a substrate holder in a plasma processing system. The focus ring comprises high resistivity silicon carbide having a resistivity greater than or equal to about 100 ohm-cm.

1 . A focus ring for surrounding a substrate on a substrate holder in a plasma processing system, comprising:
 a focus ring having an upper surface, a lower surface, an inner radial edge, and an outer radial edge, wherein said focus ring comprises high resistivity silicon carbide having a resistivity greater than or equal to about 100 ohm-cm.   
   
   
       2 . The focus ring of  claim 1 , wherein said resistivity is greater than or equal to about 1000 ohm-cm. 
   
   
       3 . The focus ring of  claim 1 , wherein said resistivity ranges from about 100 ohm-cm to about 10 6  ohm-cm. 
   
   
       4 . The focus ring of  claim 1 , wherein said focus ring consists essentially of high resistivity silicon carbide. 
   
   
       5 . The focus ring of  claim 1 , wherein said focus ring consists of high resistivity silicon carbide. 
   
   
       6 . The focus ring of  claim 1 , wherein said focus ring comprises vapor deposited high resistivity silicon carbide. 
   
   
       7 . The focus ring of  claim 1 , wherein said focus ring comprises chemical vapor deposited high resistivity silicon carbide. 
   
   
       8 . The focus ring of  claim 1 , wherein said focus ring comprises sintered high resistivity silicon carbide. 
   
   
       9 . The focus ring of  claim 1 , wherein said focus ring comprises a centering feature configured to center said focus ring on said substrate holder. 
   
   
       10 . The focus ring of  claim 1 , wherein said focus ring comprises one or more wear indicators coupled to at least one of said upper surface or said lower surface. 
   
   
       11 . The focus ring of  claim 10 , wherein said one or more wear indicators comprises a hole in said upper surface and extending to a depth from said upper surface, said depth comprising a fraction of the distance between said upper surface and said lower surface. 
   
   
       12 . The focus ring of  claim 10 , wherein said one or more wear indicators comprise a hole in said lower surface and extending to a depth from said lower surface, said depth comprising a fraction of the distance between said upper surface and said lower surface. 
   
   
       13 . The focus ring of  claim 1 , wherein said focus ring comprises a plurality of layers, wherein at least one of said plurality of layers comprises high resistivity silicon carbide. 
   
   
       14 . The focus ring of  claim 1 , wherein said focus ring comprises a coating applied to at least one of said upper surface, said lower surface, said inner radial edge, and said outer radial edge. 
   
   
       15 . The focus ring of  claim 1 , wherein said focus ring comprises a step formed in said inner radial edge.