Method for fabricating a semiconductor device including the use of a compound containing silicon and nitrogen to form an insulation film of SiN, SiCN or SiOCN

Abstract

The semiconductor device fabrication method comprises the step of forming gate electrode 20 on a semiconductor substrate 10 with a gate insulation film 18 formed therebetween; the step of implanting dopants in the semiconductor substrate 10 with the gate electrode 20 as the mask to form dopant diffused regions 28, 36 ; the step of forming a silicon oxide film 38 on the semiconductor substrate 10 , covering the gate electrodes 20 ; anisotropically etching the silicon oxide film 38 to form sidewall spacers 42 including the silicon oxide film 38 on the side walls of the gate electrode 20 . In the step of forming a silicon oxide film 38 , the silicon oxide film 38 is formed by thermal CVD at a 500-580° C. film forming temperature, using bis (tertiary-butylamino) silane and oxygen as raw materials. Silicon oxide film 38 is formed at a relatively low film forming temperature, whereby the diffusion of the dopant in the dopant diffused regions 28, 36 forming the shallow region of the extension source/drain structure can be suppressed.

1 . A method for fabricating a semiconductor device comprising the steps of forming a gate electrode on a semiconductor substrate with a gate insulation film 
 formed therebetween; implanting a dopant into the semiconductor substrate with the gate electrode as a mask to form dopant diffused regions in the semiconductor substrate on both sides of the gate electrode; and forming a silicon oxide film covering the gate electrode; and anisotropically etching the silicon oxide film to form a sidewall spacer including the silicon oxide film on the side wall of the gate electrode,    in the step of forming the silicon oxide film, the silicon oxide film being formed by thermal CVD at a 500-580° C. film forming temperature, using bis (tertiary-butylamino) silane and oxygen as raw materials.    
   
   
       2 . A method for fabricating a semiconductor device comprising the steps of forming a gate electrode on a semiconductor substrate with a gate insulation film formed therebetween; implanting a dopant into the semiconductor substrate with the gate electrode as a mask to form a dopant diffused region in the semiconductor substrate on both sides of the gate electrode; and forming a silicon oxide film covering the gate electrode; and anisotropically etching the silicon oxide film to form a sidewall spacer including the silicon oxide film on the side wall of the gate electrode, 
 in the step of forming the silicon oxide film, the silicon oxide film being formed by thermal CVD at a 560-580° C. film forming temperature, using tetra-ethyl-ortho-silicate and oxygen as raw materials.    
   
   
       3 . A method for fabricating a semiconductor device comprising the steps of forming a gate electrode on a semiconductor substrate with a gate insulation film formed therebetween; implanting a dopant into the semiconductor substrate with the gate electrode as a mask to form a dopant diffused region in the semiconductor substrate on both sides of the gate electrode; and forming a silicon oxide film covering the gate electrode; and an isotropically etching the silicon oxide film to form a sidewall spacer including the silicon oxide film on the side wall of the gate electrode, 
 in the step of forming the silicon oxide film, the silicon oxide film being formed by thermal CVD at a 600-700° C. film forming temperature for a period of film forming time of below 15 minutes, using silane and nitrous oxide as raw materials.    
   
   
       4 . A method for fabricating a semiconductor device comprising the steps of forming a gate electrode on a semiconductor substrate with a gate insulation film formed therebetween; implanting a dopant into the semiconductor substrate with the gate electrode as a mask to form a dopant diffused region in the semiconductor substrate on both sides of the gate electrode; and forming a silicon oxide film covering the gate electrode; and an isotropically etching the silicon oxide film to form a sidewall spacer including the silicon oxide film on the side wall of the gate electrode, 
 in the step of forming the silicon oxide film, the silicon oxide film being formed by thermal CVD at a 480-500° C. film forming temperature for a period of film forming time of below 30 minutes, using TEDS and ozone as raw materials.    
   
   
       5 . A method for fabricating a semiconductor device comprising the steps of forming a gate electrode on a semiconductor substrate with a gate insulation film formed therebetween; implanting a dopant into the semiconductor substrate with the gate electrode as a mask to form a dopant diffused region in the semiconductor substrate on both sides of the gate electrode; and forming a silicon oxide film covering the gate electrode; and an isotropically etching the silicon oxide film to form a sidewall spacer including the silicon oxide film on the side wall of the gate electrode, 
 in the step of forming the silicon oxide film, the silicon oxide film being formed by thermal CVD at a 500-530° C. film forming temperature for a period of film forming time of below 30 minutes, using disilane and nitrous oxide.    
   
   
       6 . A method for fabricating a semiconductor device according to  claim 1 , 
 which further comprises, after the step of forming the silicon oxide film and before the step of forming the sidewall spacer, the step of forming a silicon nitride film covering the silicon oxide film; and in which in the step of forming the silicon nitride film, the silicon nitride film is formed by thermal CVD at a 550-580° C. film forming temperature, using bis (tertiary-butylamino) silane and ammonium as raw materials,    in the step of forming the sidewall spacer, the silicon nitride film and the silicon oxide film being an isotropically etched to form the sidewall spacer including the silicon oxide film and the silicon nitride film on the side wall of the gate electrode.    
   
   
       7 . A method for fabricating a semiconductor device according to  claim 1 , which further comprises, after the step of forming the silicon oxide film and before the step of forming the sidewall spacer, the step of forming a silicon nitride film covering the silicon oxide film; and in which 
 in the step of forming the silicon nitride film, the silicon nitride film is formed by thermal CVD at a 650-700° C. film forming temperature for a period of film forming time of below 15 minutes, using silane and ammonium as raw materials,    in the step of forming the sidewall spacer, the silicon nitride film and the silicon oxide film being an isotropically etched to form the sidewall spacer including the silicon oxide film and the silicon nitride film on the side wall of the gate electrode.    
   
   
       8 . A method for fabricating a semiconductor device according to  claim 1 , which further comprises, after the step of forming the sidewall spacer, the step of implanting a dopant into the semiconductor substrate with the gate electrode and the sidewall spacer as a mask to form dopant diffused regions a carrier concentration of which is higher and which are deeper than said dopant diffused regions.  
   
   
       9 . A method for fabricating a semiconductor device according to  claim 1 , which further comprises, after the step of forming the gate electrode and before the step of forming the dopant diffused regions, the steps of: 
 forming another sidewall spacer on the side wall of the gate electrode;    implanting a dopant in the semiconductor substrate with the gate electrode and said another sidewall spacer as a mask to form dopant diffused regions a carrier concentration of which is higher and which is deeper than said dopant diffused regions; and    etching off said another sidewall spacer.    
   
   
       10 . A method for fabricating a semiconductor device according to  claim 1 , which further comprises the step of forming pocket regions of a conduction type opposite to that of said dopant diffused regions adjacent to said dopant diffused region after the step of forming a gate electrode and before the step of forming dopant diffused regions, or after the step of forming dopant diffused regions and before the step of forming the silicon oxide film.