Interior antenna for substrate processing chamber

Abstract

An interior antenna is provided for coupling RF energy to a plasma in a process chamber having a wall. The antenna comprises a coil having a face exposed to the plasma in the process chamber. A plurality of standoffs are provided to support the coil at a spacing from the wall of the process chamber. At least one standoff comprises a terminal thorough which an electrical power can be applied to the coil, the terminal comprising a conductor receptacle. A conductor cup is around the standoff having the terminal. The conductor cup comprises a sidewall having an inner diameter that is sufficiently large to maintain a sidewall gap between the sidewall and the terminal.

1 . An interior antenna for coupling RF energy to a plasma in a process chamber having a wall, the antenna comprising:
 (a) a coil having a face exposed to the plasma in the process chamber;   (b) a plurality of standoffs to support the coil at a spacing from the wall of the process chamber, at least one standoff comprising a terminal thorough which an electrical power can be applied to the coil, the terminal comprising a conductor receptacle; and   (c) a conductor cup around the standoff having the terminal, the conductor cup comprising a sidewall having an inner diameter that is sufficiently large to maintain a sidewall gap between the sidewall and the terminal.   
     
     
         2 . An antenna according to  claim 1  wherein the inner diameter of the sidewall is sufficiently large that a change in dimension of the terminal does not result in contact between the terminal and the conductor cup. 
     
     
         3 . An antenna according to  claim 1  wherein the inner diameter of the sidewall is sufficiently large that sidewall gap between the sidewall and the conductor receptacle of a standoff such that a predetermined expansion of the conductor receptacle does not result in contact between the conductor receptacle and the conductor cup. 
     
     
         4 . An antenna according to  claim 1  wherein the inner diameter of the sidewall is at least about 16 mm. 
     
     
         5 . An antenna according to  claim 1  wherein the inner diameter of the sidewall is from about 25 mm to about 30 mm. 
     
     
         6 . An antenna according to  claim 1  wherein the sidewall gap is at least about 1.5 mm. 
     
     
         7 . An antenna according to  claim 1  wherein the conductor cup further comprises an inside circumferential edge, and a bottom wall at a depth from the inside circumferential edge that is sufficiently large to provide a bottom wall gap between the bottom wall and the terminal. 
     
     
         8 . An antenna according to  claim 7  comprising at least one of (i) the depth of the bottom wall is at least about 15 mm, and (ii) the bottom wall gap is at least about 1 mm. 
     
     
         9 . An antenna according to  claim 1  wherein the coil comprises a substantially circular section and a radially inwardly bent section. 
     
     
         10 . An antenna according to  claim 1  further comprising a conductor receptacle about the terminal, the conductor receptacle having a first length L 1 , and a jacket around the conductor receptacle, the jacket having a second length L 2  that is smaller than the first length L 1 . 
     
     
         11 . An antenna according to  claim 10  wherein L 2  is smaller than L 1  by at least about 0.5 mm. 
     
     
         12 . An antenna according to  claim 1  wherein the terminal comprises an outer surface and the conductor cup comprises an inner surface encircling the standoff, and wherein at least one of the outer surface of the terminal or the inner surface of the conductor cup comprises a ceramic. 
     
     
         13 . An interior antenna for coupling RF energy to a plasma in a process chamber having a wall, the antenna comprising:
 (a) a coil having a face exposed to the plasma in the process chamber;   (b) a plurality of standoffs to support the coil at a spacing from the wall of the process chamber, at least one standoff comprising a terminal thorough which an electrical power can be applied to the coil, the terminal comprising a conductor receptacle; and   (c) a conductor cup around the standoff having the terminal, the conductor cup comprising a sidewall having an inner diameter that is sufficiently large to maintain a sidewall gap between the sidewall and the terminal such that a predetermined expansion of the conductor receptacle does not result in contact between the conductor receptacle and the conductor cup.   
     
     
         14 . An antenna according to  claim 13  wherein the sidewall gap is at least about 1.5 mm. 
     
     
         15 . An antenna according to  claim 13  wherein the inner diameter of the sidewall is at least about 16 mm. 
     
     
         16 . An antenna according to  claim 13  wherein the conductor cup further comprises an inside circumferential edge, and a bottom wall at a depth from the inside circumferential edge that maintains a bottom wall gap between the bottom wall and the terminal. 
     
     
         17 . An antenna according to  claim 13  wherein the coil comprises a substantially circular section and a radially inwardly bent section. 
     
     
         18 . An interior antenna for coupling RF energy to a plasma in a process chamber having a wall, the antenna comprising:
 (a) a coil having a face exposed to the plasma in the process chamber;   (b) a plurality of standoffs to support the coil at a spacing from the wall of the process chamber, at least one standoff comprising a terminal thorough which an electrical power can be applied to the coil, the terminal comprising an outer surface and a conductor receptacle; and   (c) a conductor cup around the standoff having the terminal, the conductor cup comprising an inner surface encircling the standoff, and a sidewall having an inner diameter that is sufficiently large to maintain a sidewall gap between the sidewall and the terminal, and wherein at least one of the outer surface of the terminal or the inner surface of the conductor cup comprises a ceramic.   
     
     
         19 . An antenna according to  claim 18  wherein the sidewall gap is at least about 1.5 mm. 
     
     
         20 . An antenna according to  claim 18  wherein the inner diameter of the sidewall is at least about 16 mm.