Patent ID: 7701030

Claim:
A device located between an isolating region and a transfer gate of a charge transfer transistor, comprising: a first photodiode having a doping profile; and a second photodiode having a doping profile reinforced relative to the doping profile of the first photodiode, wherein said device is formed by a first region of a first conductivity type above a second region of a second conductivity type formed on a semiconductor substrate, said first region comprising (a) a first zone comprising a dopant of the first conductivity type with a first concentration and having a first depth and (b) a second zone adjacent to the first zone, comprising the dopant of the first conductivity type with a second concentration higher than the first concentration and having a second depth smaller than the first depth, wherein the first photodiode comprises at least the first zone of the first region and the second photodiode comprises at least the second zone of the first region.