Protective coating for a plasma processing chamber part and a method of use

Abstract

A flexible polymer or elastomer coated RF return strap to be used in a plasma chamber to protect the RF strap from plasma generated radicals such as fluorine and oxygen radicals, and a method of processing a semiconductor substrate with reduced particle contamination in a plasma processing apparatus. The coated RF strap minimizes particle generation and exhibits lower erosion rates than an uncoated base component. Such a coated member having a flexible coating on a conductive flexible base component provides an RF ground return configured to allow movement of one or more electrodes in an adjustable gap capacitively coupled plasma reactor chamber.

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         8 . A plasma processing apparatus, comprising:
 a vacuum chamber for plasma processing a semiconductor substrate therein;   a plasma processing assembly for use in the vacuum chamber comprising a first member bonded to a second member by an elastomer bond and a silicone base elastomeric material having improved erosion resistance to plasma generated radicals, the silicone base elastomeric material surrounding the elastomer bond and sealing a mating surface of the first member to a mating surface of the second member to protect the elastomer bond from plasma generated radicals.   
     
     
         9 . The plasma processing apparatus of  claim 8 , wherein
 the plasma processing assembly comprises a temperature-controlled hot edge ring assembly surrounding a substrate support located in a lower portion of the vacuum chamber;   the first member comprises a ceramic intermediate ring overlying a lower ring, the intermediate ring attached via the lower ring to a RF electrode incorporated in the substrate support;   the second member comprises an upper ring overlying the intermediate ring, wherein the upper ring has an upper surface exposed to an interior of the vacuum chamber and a lower surface bonded to an upper surface of the intermediate ring via the elastomer bond; and   the silicone base elastomeric material surrounding the elastomer bond and sealing the upper surface of the intermediate ring to the lower surface of the upper ring to protect the elastomer bond from plasma generated radicals.   
     
     
         10 . The plasma processing apparatus of  claim 8 , wherein
 the plasma processing assembly comprises a substrate support located in a lower portion of the vacuum chamber;   the first member comprises a lower electrode assembly coupled to a radio frequency (RF) power supply;   the second member comprises an electrostatic chucking member located on an upper surface of the lower electrode assembly, the electrostatic chucking member having an upper surface which receives a substrate and a lower surface bonded to the upper surface of the lower electrode assembly by the elastomer bond; and   the silicone base elastomeric material surrounding the elastomer bond and sealing the upper surface of the lower electrode to the lower surface of the electrostatic chucking member to protect the elastomer bond from plasma generated radicals.   
     
     
         11 . The plasma processing apparatus of  claim 10 , wherein the silicone base elastomeric material is O-ring shaped. 
     
     
         12 . The plasma processing apparatus of  claim 11 , wherein the O-ring shaped silicone base elastomeric material has a polygonal cross sectional shape. 
     
     
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         18 . A method of processing a semiconductor substrate in a plasma processing apparatus, the method comprising:
 placing a substrate on a substrate support in a reaction chamber of a plasma processing apparatus of  claim 8 ;   introducing a process gas into the reaction chamber;   generating a plasma from the process gas in the reaction chamber between a top electrode assembly and the substrate;   processing the substrate with the plasma.   
     
     
         19 . The method of  claim 18 , wherein the processing comprises etching the substrate. 
     
     
         20 . The method of  claim 18 , wherein the processing includes a first step using plasma containing fluorine radicals and a second step using plasma containing oxygen radicals.