Method of manufacturing a semiconductor device

Abstract

A semiconductor device includes a first insulating film on a silicon substrate and a second insulating film on the first insulating film. The first insulating film is a silicon oxide film having a thickness of 1 nm or less and a suboxide content of 30% or less. The second insulating film is a high dielectric constant insulating film.

1 - 11 . (canceled)  
   
   
       12 . A method for manufacturing a semiconductor device, comprising: 
 treating a surface of a silicon substrate with a non-oxidizing gas under sub-atmospheric pressure;    forming a first insulating film on said silicon substrate while maintaining the sub-atmospheric pressure;    forming a metal oxide film on said first insulating film using an oxygen-containing material, said metal oxide film being a second insulating film; and    heat treating said metal oxide film in an ambient of an oxidizing gas.    
   
   
       13 . A method for manufacturing a semiconductor device, comprising: 
 treating a surface of a silicon substrate with a non-oxidizing gas under sub-atmospheric pressure;    forming a first insulating film on said silicon substrate while maintaining the sub-atmospheric pressure;    forming a metal silicate film on said first insulating film using an oxygen-containing material, said metal silicate film being a second insulating film; and    heat treating said metal silicate film in an ambient of an oxidizing gas.    
   
   
       14 . The method for manufacturing a semiconductor device according to  claim 13 , further comprising, after said heat treating, increasing nitrogen concentration of a surface of said second insulating film.  
   
   
       15 . The method for manufacturing a semiconductor device according to  claim 14 , including increasing said nitrogen concentration by heat treatment in an ambient of ammonia gas.  
   
   
       16 . The method for manufacturing a semiconductor device according to  claim 14 , including increasing said nitrogen concentrations by plasma treatments in nitrogen.  
   
   
       17 . The method for manufacturing a semiconductor device according to  claim 13 , wherein said first insulating film is a film selected from the group consisting of silicon oxide, silicon oxynitride, and silicon nitride.  
   
   
       18 . The method for manufacturing a semiconductor device according to  claim 13 , including treating said surface of said silicon substrate with said non-oxidizing gas at a temperature between 25° C. and 600° C., wherein said non-oxidizing gas is a fluorine-containing gas.  
   
   
       19 . The method as claimed in  claim 13 , wherein partial pressure of said non-oxidizing gas does not exceed 100 Pa.  
   
   
       20 . The method for manufacturing a semiconductor device according to  claim 13 , wherein: 
 said non-oxidizing gas is a fluorine-containing gas; and    said fluorine-containing gas is at least one selected from the group consisting of HF, ClF 3 , F 2 , and NF 3 .    
   
   
       21 . The method for manufacturing a semiconductor device according to  claim 13 , wherein said oxidizing gas is oxygen.  
   
   
       22 . The method for manufacturing a semiconductor device according to  claim 21 , wherein the oxygen contains one of ozone and oxygen radicals.  
   
   
       23 . The method for manufacturing a semiconductor device according to  claim 13 , including heat treating at a temperature between 100° C. and 400° C.