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 method for using a substrate processing apparatus to carry out substrate processing, said 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,   said method comprising the acts of:   forming oxygen radicals using said first radical source and forming an oxide film on a surface of said substrate by supplying said oxygen radicals to said substrate held on said stage under said first process pressure; and   forming nitrogen radicals using said second radical source and nitriding said oxide film by supplying said nitrogen radicals to said substrate held on said stage under said second process pressure.   
   
   
       2 . The method as claimed in  claim 1 , wherein said first evacuation path is activated in the state when said first radical source is activated, and said second evacuation path is activated in the state when said second radical source is activated. 
   
   
       3 . The method as claimed in  claim 1 , wherein said first radical source includes an ultraviolet source and said second radical source comprises a remote plasma source supplied with a nitrogen gas, said method further comprising:
 exciting an oxygen gas supplied to said processing vessel using said first radical source, and   causing excitation of said nitrogen gas using said second radical source.   
   
   
       4 . The method as claimed in  claim 3 , wherein said first radical source includes a nozzle causing said oxygen gas to flow along a surface of said substrate held on said stage, and said ultraviolet source is provided between said nozzle and said substrate, said ultraviolet source causing excitation of said oxygen gas through an optical window. 
   
   
       5 . The method as claimed in  claim 1 , wherein said first evacuation path includes a turbo molecular pump. 
   
   
       6 . The method as claimed in  claim 1 , wherein said second evacuation path includes a mechanical booster pump. 
   
   
       7 . The method as claimed in  claim 5 , wherein said turbo molecular pump is boosted by a mechanical booster pump. 
   
   
       8 . The method as claimed in  claim 1 , wherein said processing vessel has a substrate load/unload gate at said second end. 
   
   
       9 . The method as claimed in  claim 1 , 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. 
   
   
       10 . The method as claimed in  claim 9 , wherein said first evacuation path includes a turbo molecular pump connected to said process space via said evacuation port. 
   
   
       11 . The method as claimed in  claim 1 , wherein said stage is rotatable and said substrate processing apparatus further comprises a rotating mechanism rotating said stage. 
   
   
       12 . The method as claimed in  claim 1 , wherein said oxide film has a thickness of 0.4 nm or less. 
   
   
       13 . The method as claimed in  claim 3 , wherein a partial pressure of said oxygen gas is in the range of about 6.65 mPa-133 Pa. 
   
   
       14 . The method as claimed in  claim 3 , wherein said ultraviolet source produces ultraviolet radiation with a wavelength of 172 nm. 
   
   
       15 . The method as claimed in  claim 3 , wherein said remote plasma source excites said nitrogen gas with a frequency of 13.56 MHz or less.