Controlling Azimuthal Uniformity of Etch Process in Plasma Processing Chamber

Abstract

Apparatus, systems, and methods for controlling azimuthal uniformity of an etch process in a plasma processing chamber are provided. In one embodiment, a plasma processing apparatus can include a plasma processing chamber and an RF cage disposed above the plasma processing chamber. A dielectric window can separate the plasma processing chamber and the RF cage. The apparatus can include a plasma generating coil disposed above the dielectric window. The plasma generating coil can be operable to generate an inductively coupled plasma in the plasma processing chamber when energized. The apparatus further includes a conductive surface disposed within the RF cage proximate to at least a portion of the plasma generating coil. The conductive surface is arranged to generate an azimuthally variable inductive coupling between the conductive surface and the plasma generating coil when the plasma generating coil is energized.

1 - 20 . (canceled) 
     
     
         21 . A plasma processing apparatus, comprising:
 a cylindrical dielectric window defining a plasma processing chamber;   a plasma generating coil disposed about the dielectric window, the plasma generating coil operable to generate a plasma in the plasma processing chamber when energized with RF energy; and   a conductive surface disposed adjacent the plasma generating coil, and   wherein a first azimuthal portion of the conductive surface is located a first distance from the plasma generating coil and a second azimuthal portion of the conductive surface is located a second distance from the plasma generating coil to provide an asymmetric azimuthal profile so as to generate an azimuthally variable inductive coupling between the conductive surface and the plasma generating coil when the plasma generating coil is energized;   wherein the first distance is different than the second distance.   
     
     
         22 . The plasma processing apparatus of  claim 21 , comprising a Faraday shield disposed between the plasma generating coil and the cylindrical dielectric window. 
     
     
         23 . The plasma processing apparatus of  claim 21 , wherein the conductive surface is wrapped around the plasma generating coil. 
     
     
         24 . The plasma processing apparatus of  claim 21 , wherein the plasma generating coil and the conductive surface are disposed in an RF cage. 
     
     
         25 . The plasma processing apparatus of  claim 21 , wherein the conductive surface is configured to generate an asymmetric disturbance to the coupling between the plasma generating coil and the plasma. 
     
     
         26 . The plasma processing apparatus of  claim 21 , wherein the dielectric window comprises quartz. 
     
     
         27 . The plasma processing apparatus of  claim 21 , wherein at least a portion of the conductive surface is movable relative to the plasma generating coil. 
     
     
         28 . The plasma processing apparatus of  claim 21 , wherein the conductive surface is grounded. 
     
     
         29 . The plasma processing apparatus of  claim 22 , wherein the Faraday shield is configured to reduce capacitive coupling between the plasma generating coil and the plasma. 
     
     
         30 . The plasma processing apparatus of  claim 22 , wherein the plasma generating coil is a cylindrical plasma generating coil. 
     
     
         31 . The plasma processing apparatus of  claim 21 , wherein the first azimuthal portion of the conductive surface is bent towards the plasma generating coil. 
     
     
         32 . The plasma processing apparatus of  claim 21 , wherein the first azimuthal portion of the conductive surface is tilted towards the plasma generating coil. 
     
     
         33 . The plasma processing apparatus of  claim 21 , further comprising an adjustment mechanism operable to move the first azimuthal portion of the conductive surface relative to the plasma generating coil.