Patent ID: 7994552

Claim:
A photoelectric conversion apparatus comprising: a semiconductor substrate of a first conductivity type; a first impurity region of a second conductivity type opposite to the first conductivity type; a photoelectric conversion element including a second impurity region of the first conductivity type formed within the first impurity region, and a third impurity region of the second conductivity type formed on and adjacent to the second impurity region; and a transfer MOS transistor for transferring an electric charge accumulated in the second impurity region, wherein the first impurity region includes a surface region in which a channel of the transfer MOS transistor is formed, a first region formed under the surface region, a second region formed under the first region, and a third region formed under the second region, such that a peak impurity concentration C 0 of the surface region, a peak impurity concentration C 1 of the first region, a peak impurity concentration C 2 of the second region, and a peak impurity concentration C 3 of the third region meet a relation: C 2 <C 1 <C 0 <C 3 , and wherein the second impurity region includes a fourth region and a fifth region such that a part of at least one of the fourth and fifth regions is arranged under the transfer MOS transistor.