Plasma Reactor Having Radial Struts for Substrate Support

Abstract

A plasma reactor for processing a workpiece includes a reactor chamber having a ceiling and a sidewall and a workpiece support facing the ceiling and defining a processing region, and a pair of concentric independently excited RF coil antennas overlying the ceiling and a side RF coil concentric with the side wall and facing the side wall below the ceiling, and being excited independently.

1 - 20 . (canceled) 
     
     
         21 . A plasma reactor comprising:
 a chamber enclosing a processing region, the chamber including an axially symmetrical side wall and a ceiling overlying the side wall;   inner and outer current distributors to carry RF power to one or more conductive elements at the ceiling of the chamber to generate a plasma in the processing region;   a workpiece support having a workpiece support surface to hold a workpiece in the processing region, the workpiece support having an electrode, the workpiece support surface having a plurality of backside gas channels;   an exhaust chamber wall extending downwardly from the side wall and defining an evacuation region below the processing region;   an exhaust pump port in a bottom of the evacuation region;   a containment wall surrounded by an annular portion of the evacuation region and the exhaust chamber wall and enclosing a central region and separating the central region from the annular portion of the evacuation region, the containment wall including a floor extending below the workpiece support, the central region comprising a volume isolated from the evacuation region, the volume bounded on bottom and sides by the containment wall and on top by the workpiece support;   an annular grid between the exhaust chamber wall and the containment wall, the annular grid having a plurality axial exhaust passages between the processing region and the evacuation region;   plural radial struts below the annular grid extending between the exhaust chamber wall and the containment wall to support the containment wall;   plural radial access passages extending from the central region through the containment wall, the plural radial struts and the exhaust chamber wall, the radial access passages providing access from outside the exhaust chamber wall to the central region;   a power cable extending through one of the plural radial access passages into the central region to connect an RF power generator to the electrode; and   a gas supply line extending through one of the plural radial access passages to supply gas to the backside gas channels in the workpiece support surface.   
     
     
         22 . The plasma reactor of  claim 21 , wherein the evacuation region extends below the floor of the containment wall. 
     
     
         23 . The plasma reactor of  claim 22 , wherein the exhaust pump port is located directly below the workpiece support surface. 
     
     
         24 . The plasma reactor of  claim 21 , wherein at least some of the plurality axial exhaust passages in the annular grid are positioned over the plural radial struts. 
     
     
         25 . The plasma reactor of  claim 21 , further comprising a lift mechanism positioned in said central region and having an upper end to adjust a vertical position of the workpiece. 
     
     
         26 . The plasma reactor of  claim 25 , wherein the lift mechanism is configured to raise and lower the workpiece support relative to the floor of the containment wall. 
     
     
         27 . The plasma reactor of  claim 26 , further comprising a bellows extending between the workpiece support and the containment wall. 
     
     
         28 . The plasma reactor of  claim 21 , wherein the power cable comprises a flexible coaxial cable. 
     
     
         29 . The plasma reactor of  claim 21 , wherein the power cable comprises a rigid transmission line. 
     
     
         30 . The plasma reactor of  claim 21 , comprising a heater element in the workpiece support and a heater voltage supply line extending through one of the radial access passages and connected to the heater element. 
     
     
         31 . The plasma reactor of  claim 30 , comprising an electrostatic chucking voltage supply line connected to the electrode in the workpiece support, the electrostatic chucking voltage supply line extending through one of the radial access passages. 
     
     
         32 . The plasma reactor of  claim 30 , wherein different utilities extend through different ones of the radial access passages. 
     
     
         33 . The plasma reactor of  claim 21 , wherein the side wall and containment wall are coaxial. 
     
     
         34 . The plasma reactor of  claim 21 , wherein the plural radial struts are spaced at equal angular intervals around the containment wall. 
     
     
         35 . The plasma reactor of  claim 21 , wherein the plural radial struts consist of exactly three radial struts.