Field effect transistor with metal oxide gate insulator and sidewall insulating film

Abstract

Provided is a semiconductor device including a silicon substrate, a gate insulator disposed on the silicon substrate and containing a metal oxide, a gate electrode disposed on the gate insulator, and a sidewall insulating film disposed on a side of the gate insulator and the gate electrode and containing aluminum, silicon, oxygen and nitrogen.

1 - 14 . (canceled)  
   
   
       15 . A method of manufacturing a semiconductor device, comprising: 
 forming a gate insulator containing a metal oxide on a silicon substrate;    forming a gate electrode on the gate insulator;    forming a sidewall insulating film containing aluminum, silicon, oxygen and nitrogen on a side of the gate insulator and gate electrode; and    after forming the sidewall insulating film, introducing an impurity into a surface region of the silicon substrate by ion implantation.    
   
   
       16 . The method according to  claim 15 , wherein the sidewall insulating film has a network structure constructed by aluminum, silicon, nitrogen and oxygen.  
   
   
       17 . The method according to  claim 15 , wherein at least a part of the sidewall insulating film has a composition represented by a general formula:  
       Si 6-z Al z O z N 8-z    where z is a value larger than 0 and smaller than 6.    
   
   
       18 . The method according to  claim 15 , wherein a sum of concentrations of aluminum, silicon, oxygen and nitrogen in the sidewall insulating film is equal to or larger than 97 atomic %.  
   
   
       19 . The method according to  claim 15 , wherein a material of the gate insulator is silicate of the metal oxide and silicon dioxide, and the metal oxide contains as a constituent metal element thereof at least one metal element selected from the group consisting of zirconium, hafnium, lanthanum, cerium, titanium, yttrium, tantalum, bismuth and praseodymium.  
   
   
       20 . The method according to  claim 15 , wherein the gate insulator consists essentially of the metal oxide, and the metal oxide contains as a constituent metal element thereof at least one metal element selected from the group consisting of zirconium, hafnium, lanthanum, cerium, titanium, yttrium, tantalum, bismuth and praseodymium.