Patent ID: 7592579

Claim:
A photoelectric conversion device manufacturing method comprising: an oxide film formation step of forming an oxide film on a surface of an underlying substrate including an element region and an element isolation region; a mask formation step of forming, on the oxide film, a mask having an opening in the element region; a first implantation step of implanting impurity ions of a first conductivity type into the underlying substrate via a region of the oxide film exposed by the opening, thereby forming a first semiconductor region having a first thickness in the underlying substrate under the oxide film in the element region; an oxidation step of oxidizing the region of the oxide film exposed by the opening, thereby thickening the exposed region; an exposure step of exposing a region of the oxide film which is not exposed by the opening; a second implantation step of, after the exposure step, implanting the impurity ions of the first conductivity type into the underlying substrate via a region unthickened in the oxidation step, thereby forming a second semiconductor region having a second thickness larger than the first thickness in the underlying substrate under the oxide film in the element isolation region; and an element formation step of, after the second implantation step, forming a photoelectric conversion unit above the first semiconductor region, the photoelectric conversion unit including a third semiconductor region of a second conductivity type opposite to the first conductivity type and accumulating a photoelectrically converted signal.