Semiconductor device and method for producing same

A method for producing a semiconductor device comprising:

• forming an element isolation insulating film in a surface layer portion of a semiconductor substrate, the surface layer portion including a region of a first conductivity type, the element isolation insulating film defining a photodiode region and a transistor region in an active region;
• forming a first diffusion region of a second conductivity type in the active region;
• forming a shielding layer of the first conductivity type in a region between the first diffusion region and a surface of the semiconductor substrate;
• forming a gate pattern in the transistor region, the gate pattern including a gate insulating film and a gate electrode that are stacked;
• forming an insulating film configured to cover the gate pattern and the surface of the semiconductor substrate;
• forming a first mask pattern configured to allow the transistor region to be exposed therethrough, the first mask pattern having an opening located on part of the photodiode region;
• subjecting the insulating film to anisotropic etching with the first mask pattern as an etching mask to form an opening in the insulating film and leave sidewall spacers composed of the insulating film on the sides of the gate pattern;
• removing the first mask pattern;
• implanting an impurity of the second conductivity type into the semiconductor substrate with the insulating film as a mask to form a third diffusion region in the photodiode region;
• and
• forming a metal silicide film on the third diffusion region.