Radical processing of a sub-nanometer insulation film

Abstract

A method of nitriding an insulation film, includes the steps of forming nitrogen radicals by high-frequency plasma, and causing nitridation in a surface of an insulation film containing therein oxygen, by supplying the nitrogen radicals to the surface of the insulation film.

1 . A substrate processing apparatus, comprising: 
 a nitrogen radical formation unit forming nitrogen radicals with high-frequency plasma; and a processing vessel holding a substrate formed with an insulation film,    said processing vessel causing nitridation of a surface of said insulation film by being supplied with said nitrogen radicals form said    nitrogen radical formation unit and supplying said nitrogen radicals to said surface of said insulation film.    
   
   
       2 . The substrate processing apparatus as claimed in  claim 1 , wherein said processing vessel carries said nitrogen radical formation unit on a sidewall surface thereof, said processing vessel supplying said nitrogen radicals to said surface of said insulation film in the form of being carried by a gas flow caused to flow along said surface of said insulation film.  
   
   
       3 . The substrate processing apparatus as claimed in  claim 2 , wherein said gas flow is formed in said processing vessel so as to flow from a first side of said substrate formed with said insulation film to a second, diametrically opposite side to said first side.  
   
   
       4 . The substrate processing apparatus as claimed in  claim 3 , wherein said processing vessel is evacuated at said second side of said substrate.  
   
   
       5 . The substrate processing apparatus as claimed in  claim 1 , wherein said radical formation unit comprises a gas passage and a high-frequency plasma formation part formed in a part of said gas passage for causing plasma excitation in a nitrogen gas flowing through said gas passage.  
   
   
       6 . The substrate processing apparatus as claimed in  claim 5 , wherein said high-frequency plasma formation unit causes said plasma excitation of said nitrogen gas at a frequency of 400-500 kHz.  
   
   
       7 . The substrate processing apparatus as claimed in  claim 1 , wherein said processing vessel is connected with an evacuation system capable of evacuating an interior space of said processing vessel to a pressure lower than a pressure used in said nitridation step of said insulation film surface.  
   
   
       8 . A substrate processing apparatus, comprising: 
 a processing vessel defining a process space, said processing vessel accommodating a stage holding a substrate in said process space;    a first radical source provided on said processing vessel at a side of a first end of said processing vessel with respect to said stage;    a second radical source provided on said processing vessel at a side of said first end of said processing vessel with respect to said stage;    a first evacuation path provided on said processing vessel at a side of a second end of said processing vessel opposite to said first end, said first evacuation path evacuating said process space to a first process pressure; and    a second evacuation path provided on said processing vessel at a side of said second end of said processing vessel, said second evacuation path evacuating said process space to a second process pressure.    
   
   
       9 . The substrate processing apparatus as claimed in  claim 8 , wherein said first evacuation path is activated in the state when said first 
 radical source is activated, and wherein said second evacuation path is activated in the state when said second radical source is activated.    
   
   
       10 . The substrate processing apparatus as claimed in  claim 8 , wherein said first radical source includes an ultraviolet source exciting an oxygen gas supplied to said processing vessel, and wherein said second radical source comprises a remote plasma source supplied with a nitrogen gas and causing excitation of said nitrogen gas.  
   
   
       11 . The substrate processing apparatus as claimed in  claim 10 , wherein said first radical source includes a nozzle causing to flow said oxygen gas along a surface of said substrate held on said stage, and wherein said ultraviolet source is provided between said nozzle and said substrate so as to cause excitation of said oxygen gas through an optical window.  
   
   
       12 . The substrate processing apparatus as claimed in  claim 8 , wherein said first evacuation path includes a turbo molecular pump.  
   
   
       13 . The substrate processing apparatus as claimed in  claim 8 , wherein said second evacuation path includes a mechanical booster pump.  
   
   
       14 . The substrate processing apparatus as claimed in  claim 12 , wherein said turbo molecular pump is boosted by a mechanical booster pump.  
   
   
       15 . The substrate processing apparatus as claimed in  claim 8 , wherein said processing vessel has a substrate load/unload gate at said second end.  
   
   
       16 . The substrate processing apparatus as claimed in  claim 8 , wherein both of said first evacuation path and said second evacuation path evacuate said process space via an evacuation port provided in said processing vessel in the vicinity of said second end.  
   
   
       17 . The substrate processing apparatus as claimed in  claim 16 , wherein said first evacuation path includes a turbo molecular pump connected to said process space via said evacuation port.  
   
   
       18 . The substrate processing apparatus as claimed in  claim 8 , wherein said state is provided rotatably and wherein said substrate processing apparatus further comprises a rotating mechanism rotating said stage.  
   
   
       19 . A substrate processing apparatus, comprising: 
 a processing vessel defining a process space, said processing vessel accommodating a state holding a substrate in said process space;    a first radical source provided on said processing vessel;    a second radical source provided on said processing vessel;    a first evacuation path provided on said processing vessel, said first evacuation path evacuating said process space to a first process pressure; and    a second evacuation path provided on said processing vessel, said second evacuation path evacuating said process space to a second process pressure,    wherein said first processing path is provided so as to evacuate said process space at a side opposite to said first radical source with respect to said substrate on said stage, and wherein said second evacuation path is provided so as to evacuate said process space at a side opposite to said second radical source with respect to said substrate on said stage.    
   
   
       20 . A cluster-type substrate processing apparatus, comprising: 
 a substrate transfer chamber; and    a plurality of process chambers connected to said substrate transfer chamber, one of said plurality of process chambers comprising:    a processing vessel having a substrate load/unload opening at a first end thereof in connection with said substrate transfer chamber and a first radical source at a second end opposite to said first end, said processing vessel defining a process space therein;    a stage provided in said process space between said first end and said second end in a rotatable manner, said stage holding a substrate thereon;    a first process gas inlet provided in said process space between said first end and said stage, said first process gas inlet introducing a first process gas into said process space;    a second radical source provided on said processing vessel so as to cause excitation of said fist process gas between said first gas inlet and said stage;    a first evacuation port provided in said process space at a part closer to said first end with respect to said stage;    a second evacuation port provided in said process space at a side closer to said second end with respect to said stage;    a first pump connected to said first evacuation port so as to evacuate said process space to a first process pressure; and    a second pump connected to said second evacuation port so as to evacuate said process space to a second process pressure lower than said first process pressure, wherein said second pump is disposed in the vicinity of said second end of said processing vessel.    
   
   
       21 . A semiconductor device, comprising: 
 a silicon substrate; and    an insulation film formed on said silicon substrate with a thickness of 2-4 atomic layers.    
   
   
       22 . The semiconductor device as claimed in  claim 21 , wherein said insulation film has a uniform thickness within the range of 2-4 atomic layers.  
   
   
       23 . The semiconductor device as claimed in  claim 21 , wherein said insulation film comprises an oxide film.  
   
   
       24 . The semiconductor device as claimed in  claim 21 , wherein said insulation film comprises a silicon oxynitride film.  
   
   
       25 . The semiconductor device as claimed in  claim 21 , further comprising a high-K dielectric film formed on said insulation film and a gate electrode formed on said high-K dielectric film.  
   
   
       26 . A semiconductor device, comprising: a silicon substrate; and 
 an insulation film formed on said silicon substrate,    said insulation film is formed by nitriding an oxide film formed on said silicon substrate with a thickness of 1-4 atomic layers.