Patent ID: 8378396

Claim:
A photoelectric conversion device comprising: a pixel comprised of a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type disposed in the first semiconductor region, a first diffusion region of the first conductivity type held at a predetermined potential and covering entirely the first semiconductor region and covering only a part of an upper portion of the second semiconductor region, a second diffusion region of the second conductivity type disposed above the second semiconductor region and the first diffusion region and covering a part of the upper portion of the second semiconductor region except for the part of the upper portion of the second semiconductor region covered by the first diffusion region, and a field oxide film having a thick portion and a thin portion, the thick portion of the field oxide film covering the upper portion of the second semiconductor region except for a portion of the part of the upper portion of the second semiconductor region covered by the second diffusion region, the first diffusion region being disposed entirely under the thick portion of the field oxide film, and the thin portion of the field oxide film being disposed directly in contact with the second diffusion region but not the first semiconductor region, second semiconductor region and first diffusion region.