Patent ID: 7943962

Claim:
A method for producing a solid-state image pickup device in which a plurality of pixels including a photoelectric conversion part having a charge accumulation region accumulating signal charges is two-dimensionally arrayed in a well region formed in a semiconductor substrate, the method comprising the steps of: forming an element isolation insulating film over the surface of the well region, the element isolation insulating film electrically isolating the pixels; forming a first isolation diffusion region in the well region, the first isolation diffusion region electrically isolating the pixels and; forming a second isolation diffusion region in the well region, the second isolation diffusion region electrically isolating the pixels which is under the first isolation diffusion region and wherein a width of said second isolation diffusion region is smaller than that of said first isolation diffusion region; and forming the photoelectric conversion part for each pixel in the well region in which the photoelectric conversion part is electrically isolated from each other by the element isolation insulating film, the first isolation diffusion region, and the second isolation diffusion region, wherein the step of forming the photoelectric conversion part includes the steps of implanting an impurity ion for forming the charge accumulation region in the well region surrounded by the first isolation diffusion region and the second isolation diffusion region and the projecting region of first isolation diffusion region; and thermally diffusing the impurity implanted in the well region by the step of ion implantation so that a part of the charge accumulation region corresponding to the boundary between the charge accumulation region and the second isolation diffusion region is disposed under the first isolation diffusion region and is abutted or disposed close to the second isolation diffusion layer.