Inductively Coupled Plasma Source with Multiple Dielectric Windows and Window Supporting Structure

Abstract

A plasma reactor enclosure has a metallic portion and a dielectric portion of plural dielectric windows supported on the metallic portion, each of the dielectric windows extending around an axis of symmetry. Plural concentric coil antennas are disposed on an external side of the enclosure, respective ones of the coil antennas facing respective ones of the dielectric windows.

1 - 20 . (canceled) 
     
     
         21 . A plasma reactor comprising:
 an enclosure having an axis of symmetry and a workpiece support within the enclosure, the workpiece support and the enclosure defining a processing region, the enclosure including
 a cylindrical metallic portion, 
 a cylindrical dielectric window extending around the said axis of symmetry and supported on the metallic portion, a bottom edge of the cylindrical dielectric window positioned above the workpiece support such that a workpiece on the workpiece support is supported below the bottom edge, 
 a metallic plate having a central opening and supported on the cylindrical dielectric window, and 
 a disk-shaped dielectric window supported on the plate and extending around the said axis of symmetry and overlying the central opening, a bottom face of the disk-shaped dielectric window positioned above a top edge of the cylindrical dielectric window, an inner diameter of cylindrical dielectric window being greater than an outer diameter of the disk-shaped dielectric window; and 
   a plural concentric coil antennas disposed on an external side of said enclosure, the plural concentric coil antennas including a first coil antenna positioned above and facing the disk-shaped window, and a second coil antenna surrounding and facing the cylindrical dielectric window.   
     
     
         22 . The plasma reactor of  claim 21 , wherein the disk-shaped dielectric window has a circular edge portion supported on an edge of said central opening. 
     
     
         23 . The plasma reactor of  claim 21 , wherein the metallic plate provides an annular top gas plate having a peripheral portion supported on the cylindrical dielectric window. 
     
     
         24 . The plasma reactor of  claim 23 , wherein the top gas plate has plural gas injection orifices circularly arranged about the peripheral portion. 
     
     
         25 . The plasm reactor of  claim 24 , further comprising a center gas disperser in a center of said disk-shaped dielectric window and disposed to introduce gas into the processing region. 
     
     
         26 . The plasma reactor of  claim 21 , wherein the metallic plate abuts the top edge of the cylindrical dielectric window. 
     
     
         27 . The plasma reactor of  claim 21 , the metallic plate comprises a planar bottom surface extending inwardly from the top edge of the cylindrical dielectric window. 
     
     
         28 . The plasma reactor of  claim 21 , wherein the metallic plate extends radially outward past the dielectric window. 
     
     
         29 . The plasma reactor of  claim 28 , comprising at least one insulator extending axially through the metallic plate, and an axial conductor extending through the insulator and connected to the second coil antenna to supply RF power to the second coil antenna. 
     
     
         30 . The plasma reactor of  claim 21 , comprising a third coil antenna, the third coil antenna disposed over and facing the disk-shaped dielectric window and concentric and surrounding the first coil antenna. 
     
     
         31 . The plasma reactor of  claim 21 , further comprising a first heater layer on the disk-shaped dielectric window. 
     
     
         32 . The plasma reactor of  claim 31 , further comprising a second heater layer on the cylindrical dielectric window. 
     
     
         33 . The plasma reactor of  claim 21 , wherein the workpiece support comprises a pedestal and a post to hold the pedestal above a bottom of the processing region. 
     
     
         34 . The plasma reactor of  claim 33 , wherein the cylindrical metallic portion extends to the bottom of the processing region.