Semiconductor device

Abstract

A semiconductor device includes a substrate, and a gate electrode on the substrate via a gate insulating film. The gate insulating film includes a base interface layer on the substrate, metal silicate film on the base interface layer and containing a metal, oxygen, and silicon, and a nitrogen-containing metal silicate film on the metal silicate film, and containing the metal, oxygen, silicon, and nitrogen and including nitrogen in a range from ten atomic % to thirty atomic %, and the metal silicate film contains the metal in a concentration higher than metal concentration of said nitrogen-containing metal silicate film.

1 . (canceled)  
   
   
       2 . A semiconductor device comprising: 
 a substrate;    a gate insulating film on said substrate, and including: 
 a base interface layer on said substrate,  
 a metal silicate film on said base interface layer, and containing a metal, oxygen, and silicon, and  
 a nitrogen-containing metal silicate film that contains said metal, oxygen, silicon, and nitrogen, and including ten to thirty atomic percent nitrogen; and  
   a gate electrode on said gate insulating film, wherein said metal silicate film has a metal concentration higher than metal concentration of said nitrogen-containing metal silicate film.    
   
   
       3 . The semiconductor device according to  claim 2 , wherein said nitrogen-containing metal silicate film contains said metal in a concentration in a range from one to thirty atomic percent.  
   
   
       4 . The semiconductor device according to  claim 3 , wherein said metal silicate film contains said metal in a concentration in a range from five to forty atomic percent.  
   
   
       5 - 20 . (canceled)  
   
   
       21 . The semiconductor device as claimed in  claim 2 , wherein metal concentration of said metal silicate film is two times silicon concentration of said metal silicate film.  
   
   
       22 . The semiconductor device according to  claim 2 , wherein metal concentration of said nitrogen-containing metal silicate film is four times silicon concentration of said nitrogen-containing metal silicate film.