Solid-state imaging device and method for producing the same

Abstract

A method for producing a solid-state imaging device, which including: a photoelectric conversion section; a charge transfer section having a charge transfer electrode; and an antireflection film covering a light-receiving region in the photoelectric conversion section, wherein forming the antireflection film includes: forming a sidewall on a lateral wall of the charge transfer electrode after forming the charge transfer electrode; forming an antireflection film on a substrate surface where the sidewall is formed; forming a resist on the antireflection film; melting and flattening the resist to expose the antireflection film on the charge transfer electrode; removing the antireflection film by using the resist as the mask; removing the sidewall; covering the charge transfer electrode with an insulating film; and forming a light-shielding film that reaches a level lower than the top surface of the antireflection film, and that surrounds the periphery of the antireflection film.

1 . A method for producing a solid-state imaging device, which comprises: 
 a photoelectric conversion section;    a charge transfer section having a charge transfer electrode for transferring an electric charge generated in the photoelectric conversion section; and    an antireflection film covering a light-receiving region in the photoelectric conversion section,    wherein    forming the antireflection film comprises:    forming a sidewall on a lateral wall of the charge transfer electrode after forming the charge transfer electrode;    forming an antireflection film on a substrate surface where the sidewall is formed;    forming a resist on the antireflection film;    melting and flattening the resist to expose the antireflection film on the charge transfer electrode;    removing the antireflection film by using the resist as the mask;    removing the sidewall;    covering the charge transfer electrode with an insulating film; and    forming a light-shielding film that reaches a level lower than the top surface of the antireflection film, and that surrounds the periphery of the antireflection film.    
     
     
         2 . The method for producing the solid-state imaging device as claimed in  claim 1 , wherein the forming of the light-shielding film comprises patterning by photolithography after the forming of the light-shielding film.  
     
     
         3 . The method for producing the solid-state imaging device as claimed in  claim 1 , which comprises, 
 etching at least a part of an gate oxide film on the photoelectric conversion section by using the charge transfer electrode as the mask, the etching performing in advance of the forming of the sidewall.    
     
     
         4 . The method for producing the solid-state imaging device as claimed in  claim 3 , wherein the etching of the gate oxide film is exposing the substrate surface.  
     
     
         5 . The method for producing the solid-state imaging device as claimed in  claim 4 , which comprises, 
 covering the substrate surface with an oxide film by a radical oxidation using a low-temperature plasma after the exposing of the substrate surface.    
     
     
         6 . The method for producing the solid-state imaging device as claimed in  claim 1 , wherein the forming of the sidewall comprises forming a polycrystalline silicon layer by a chemical vapor deposition method.  
     
     
         7 . The method for producing the solid-state imaging device as claimed in  claim 1 , wherein the forming of the insulating film comprises forming a silicon oxide film by a radical oxidation using a low-temperature plasma.  
     
     
         8 . The method for producing the solid-state imaging device as claimed in  claim 1 , wherein the forming of the antireflection film is forming a silicon nitride film.  
     
     
         9 . A solid-state imaging device comprising: 
 a photoelectric conversion section;    a charge transfer section having a charge transfer electrode for transferring an electric charge generated in the photoelectric conversion section;    an antireflection film covering a light-receiving region of the photoelectric conversion section; and    a light-shielding film reaching a level lower than the top surface of the antireflection film, and surrounding the periphery of the antireflection film.    
     
     
         10 . The solid-state imaging device as claimed in  claim 9 , wherein at least a part of the gate oxide film formed in the charge transfer section is removed on the photoelectric conversion section.  
     
     
         11 . The solid-state imaging device as claimed in  claim 10 , 
 wherein    the gate oxide film is removed on the surface of the photoelectric conversion section, and    an antireflection film is formed on the surface of the photoelectric conversion section through a radical oxide film provided by using a low-temperature plasma.    
     
     
         12 . The solid-state imaging device as claimed in  claim 9 , wherein a silicon oxide film formed by a radical oxidation using a low-temperature plasma is intervening between the antireflection film and the light-shielding film.  
     
     
         13 . The solid-state imaging device as claimed in  claim 9 , wherein the antireflection film is a silicon nitride film.  
     
     
         14 . The solid-state imaging device as claimed in  claim 9 , wherein the light-shielding film is tungsten.  
     
     
         15 . The solid-state imaging device as claimed in  claim 14 , wherein the tungsten film is formed through a titanium nitride layer.