Patent ID: 8309997

Claim:
A photoelectric conversion device comprising: a semiconductor substrate of a first conductive type; a photoelectric conversion element that includes a first semiconductor region of a second conductive type arranged on the semiconductor substrate and a second semiconductor region of the first conductive type arranged to form a PN junction with the first semiconductor region and a transfer gate for transferring a charge accumulated in the second semiconductor region to a floating diffusion, wherein the first semiconductor region has an impurity distribution such that a plurality of impurity concentration peaks are formed along a direction of depth, in which a first impurity concentration peak located most deeply among all of the peaks with respect to a light receiving surface of the photoelectric conversion element is highest, a second impurity concentration peak located in a vicinity of the second semiconductor region is lower than the first impurity concentration peak, and a third impurity concentration peak located between the first and second impurity concentration peaks is lower than the first and second impurity concentration peaks, and wherein a part of the second semiconductor region is disposed under a part of the transfer gate within the first semiconductor region.