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 - 10 . (canceled)  
   
   
       11 . A method for manufacturing a semiconductor device comprising: 
 forming a gate insulating film on a silicon substrate;    forming a gate electrode on the gate insulating film; and    forming an electrical insulating film on the gate electrode,    wherein the electrical insulating film is formed by using a gas mixture as a source gas to form a silicon nitride film at temperatures of 750° C. to 800° C., and the gas mixture comprises at least one gas selected from the group consisting of monosilane, dichlorosilane, and trichlorosilane and at least one gas selected from the group consisting of ammonia, dimethylamine, hydrazine, and dimethylhydrazine as a gas including a N—H bond.    
   
   
       12 . The method according to  claim 11 , wherein annealing is performed after the formation of the silicon nitride film so that an annealing temperature is higher than a temperature at which the silicon nitride film is formed.  
   
   
       13 . The method according to  claim 12 , wherein the annealing temperature is 800° C. to 1200° C.  
   
   
       14 . The method according to  claim 12 , wherein the annealing is performed in an atmosphere containing an inert gas.  
   
   
       15 . The method according to  claim 12 , wherein the annealing is performed in an atmosphere of reduced pressure.  
   
   
       16 . The method according to  claim 11 , wherein the gate electrode comprises a polysilicon film implanted with boron ions, a metal film, or a laminated structure of a polysilicon film and a metal film.