Inductive plasma source with metallic shower head using b-field concentrator

Abstract

A method and apparatus for plasma processing of substrates is provided. A processing chamber has a substrate support and a lid assembly facing the substrate support. The lid assembly has a plasma source that comprises an inductive coil disposed within a conductive plate, which may comprise nested conductive rings. The inductive coil is substantially coplanar with the conductive plate, and insulated therefrom by an insulator that fits within a channel formed in the conductive plate, or nests within the conductive rings. A field concentrator is provided around the inductive coil, and insulated therefrom by isolators. The plasma source is supported from a conductive support plate. A gas distributor supplies gas to the chamber through a central opening of the support plate and plasma source from a conduit disposed through the conductive plate.

1 . A lid assembly for a plasma chamber, comprising:
 a first annular inductive coil nested with a first conductive ring.   
     
     
         2 . The lid assembly of  claim 1 , wherein the first annular inductive coil is disposed in an insulating channel nested with the first conductive ring. 
     
     
         3 . The lid assembly of  claim 2 , further comprising a field concentrator disposed around the first annular inductive coil inside the insulating channel. 
     
     
         4 . The lid assembly of  claim 3 , further comprising a second annular inductive coil disposed in a second insulating channel nested with the first conductive ring. 
     
     
         5 . The lid assembly of  claim 4 , wherein the first and second annular inductive coils and the first conductive ring are arranged concentrically. 
     
     
         6 . The lid assembly of  claim 4 , wherein the first and second annular inductive coils each comprise a metal tube. 
     
     
         7 . The lid assembly of  claim 6 , wherein the first annular inductive coil is nested in a central opening of the conductive ring and the second annular inductive coil is nested about a peripheral edge of the conductive ring. 
     
     
         8 . A lid assembly for a plasma chamber, comprising:
 a gas distributor;   a support plate disposed around the gas distributor;   a conductive ring disposed around the gas distributor and coupled to the support plate;   an annular inductive coil disposed in an insulating channel nested with the conductive ring; and   a field concentrator disposed in the insulating channel around the inductive coil.   
     
     
         9 . The lid assembly of  claim 8 , wherein the insulating channel is concentrically disposed in a central opening of the conductive ring, has an opening that faces the support plate, and has an extension over an inner edge of the conductive ring. 
     
     
         10 . The lid assembly of  claim 9 , wherein the support plate is conductive and is electrically coupled to the conductive ring. 
     
     
         11 . The lid assembly of  claim 8 , wherein the gas distributor is coupled to a conduit through a central aperture of the support plate, the conductive ring, and the annular inductive coil, the support plate is electrically coupled to the conductive ring, the annular conductive coil is electrically insulated from the support plate and the conductive ring, and the annular conductive coil is substantially coplanar with the conductive ring. 
     
     
         12 . The lid assembly of  claim 8 , further comprising an isolator disposed in the insulating channel, the isolator having a channel into which the annular inductive coil fits. 
     
     
         13 . The lid assembly of  claim 12 , wherein the annular inductive coil is substantially coplanar with the conductive ring. 
     
     
         14 . The lid assembly of  claim 13 , wherein the annular inductive coil comprises a conduit for a thermal control medium. 
     
     
         15 . A processing chamber for a semiconductor substrate, comprising:
 a chamber body defining an interior region;   a substrate support disposed in the interior region; and   a lid assembly disposed in the interior region facing the substrate support, the lid assembly comprising:
 a gas distributor; and 
 a plasma source having a first conductive surface that faces the substrate support, a second conductive surface that faces away from the substrate support, and a plurality of conductive coils disposed in the conductive plasma source between the first surface and the second surface. 
   
     
     
         16 . The processing chamber of  claim 15 , wherein each the conductive coils is disposed in a conduit formed in the conductive plasma source, and the conduit is lined with an insulating material. 
     
     
         17 . The processing chamber of  claim 16 , wherein a magnetic field concentrator is disposed within the conduit. 
     
     
         18 . The processing chamber of  claim 17 , wherein each conductive coil is formed with an internal pathway for a thermal control medium. 
     
     
         19 . The processing chamber of  claim 18 , wherein each conductive coil comprises a plurality of conductive loops separated by insulators. 
     
     
         20 . A method of processing a substrate, comprising:
 disposing the substrate on a substrate support in a processing chamber;   providing a plasma source facing the substrate support, the plasma source comprising a plurality of conductive loops disposed in an electrode, to define a processing region between the plasma source and the substrate support;   providing a gas mixture to the processing region;   grounding the electrode; and   forming a plasma from the gas mixture by applying electric power to the conductive loops.   
     
     
         21 . The method of  claim 20 , further comprising tuning the plasma profile by applying different power levels to the conductive loops. 
     
     
         22 . The method of  claim 21 , further comprising circulating a cooling medium through the conductive loops. 
     
     
         23 . The method of  claim 22 , wherein the gas mixture is provided to the processing region through an aperture in a central portion of the plasma source. 
     
     
         24 . The method of  claim 22 , wherein the gas mixture is provided to the processing region through a plurality of apertures in the plasma source.