Semiconductor device and method for manufacturing the same

Abstract

A semiconductor device includes a gate insulating film formed on a silicon substrate, a gate electrode formed on the gate insulating film, and an electrical insulating film formed on the gate electrode. The electrical insulating film includes a N—H bond and substantially no Si—H bond. The electrical insulating film is formed by using tetrachlorosilane (SiCl 4 ) that contains no hydrogen (H) as a source gas for a silicon nitride film. Thus, the semiconductor device can suppress residual hydrogen in the gate insulating film and prevent interface defects of the gate insulating film, a shift in the threshold voltage of a transistor, and the degradation of an on-state current. A method for manufacturing the semiconductor device also is provided.

1 . A semiconductor device comprising: 
 a gate insulating film formed on a silicon substrate; and    a gate electrode formed on the gate insulating film;    wherein the gate electrode comprises a deposited film and a gate cap insulating film formed on the deposited film, the deposited film comprising a polysilicon film, a metal film, or a laminated structure of a polysilicon film and a metal film, and    the gate cap insulating film includes a N—H bond and substantially no Si—H bond.    
   
   
       2 . The semiconductor device according to  claim 1 , wherein the gate cap insulating film is a silicon nitride film.  
   
   
       3 . The semiconductor device according to  claim 1 , wherein the gate cap insulating film is a deposited film obtained by decomposition of a mixture of a gas including substantially no Si—H bond and a gas including a N—H bond.  
   
   
       4 . The semiconductor device according to  claim 3 , wherein the gas including substantially no Si—H bond is a tetrachlorosilane gas, and the gas including a N—H bond is at least one gas selected from the group consisting of ammonia, dimethylamine, hydrazine, and dimethylhydrazine.  
   
   
       5 . The semiconductor device according to  claim 1 , wherein the polysilicon film is implanted with boron ions.  
   
   
       6 - 16 . (canceled)