Low Electron Temperature Etch Chamber with Independent Control Over Plasma Density, Radical Composition Ion Energy for Atomic Precision Etching

Abstract

The disclosure concerns a method of operating a plasma reactor having an electron beam plasma source for independently adjusting electron beam energy, plasma ion energy and radical population. The disclosure further concerns an electron beam source for a plasma reactor having an RF-driven electrode for producing the electron beam.

1 - 8 . (canceled) 
     
     
         9 . A plasma reactor for processing a workpiece, comprising:
 an electron beam gun enclosure having a beam outlet opening at one end of said enclosure and enclosing an electron emission electrode at an opposite end of said enclosure, said electron emission electrode having an electron emission surface facing said beam outlet, said beam outlet and said electron emission electrode defining a beam propagation path between them;   an RF power source and an RF power conductor coupled between said RF power source and said electron emission electrode; and   a processing chamber having a beam entry port aligned with said beam outlet, a workpiece support in said processing chamber for supporting a workpiece in a plane parallel with said beam propagation path, and a gas distributor coupled to said processing chamber.   
     
     
         10 . The plasma reactor of  claim 9  wherein said RF power source comprises a first RF power generator and an impedance match coupled between said first RF power generator and said electron emission electrode. 
     
     
         11 . The plasma reactor of  claim 10  wherein said impedance match comprises a dual frequency impedance match, said power source further comprising a second RF power generator having a frequency different from a frequency of said first RF power generator. 
     
     
         12 . The plasma reactor of  claim 11  wherein said first RF power generator produces a low frequency and said second RF power generator produces a high frequency. 
     
     
         13 . The plasma reactor of  claim 9  further comprising a gas supply having a feed path into said electron beam gun enclosure. 
     
     
         14 . The plasma reactor of  claim 13  further comprising an ion-blocking filter in said beam outlet opening, said ion-blocking filter permitting flow of electrons through said beam outlet. 
     
     
         15 . The plasma reactor of  claim 9  further comprising:
 a backing plate insulated from said electron gun enclosure and contacting a back face of said electron emitting electrode; 
 a chiller plate contacting said backing plate; and 
 wherein said RF power conductor is connected to said chiller plate. 
 
     
     
         16 . The plasma reactor of  claim 15  further comprising an insulator surrounding an edge of said electron emitting electrode and disposed between said electron emitting electrode and said electron gun enclosure. 
     
     
         17 . The plasma reactor of  claim 9  further comprising a process gas supply coupled to said gas distributor. 
     
     
         18 . The plasma reactor of  claim 11  further comprising a remote plasma source coupled to said processing chamber. 
     
     
         19 . The plasma reactor of  claim 18  further comprising a bias power generator coupled to said workpiece support. 
     
     
         20 . The plasma reactor of  claim 19  wherein said first RF power generator, said second RF power generator, said bias power generator and said remote plasma source are independently controllable.