Abstract: A photoelectric conversion device includes a connecting portion that electrically connects a contact plug of anode wiring and the second semiconductor region of the isolation portion. The connecting portion includes a third semiconductor region of the second conducting type that is connected to the contact plug of the anode wiring, and a fourth semiconductor region of the second conducting type that is disposed between the third semiconductor region and the second semiconductor region. The impurity concentration of the third semiconductor region is higher than the impurity concentration of the second semiconductor region and the impurity concentration of the fourth semiconductor region is lower than the impurity concentration of the third semiconductor region. With respect to a direction in which the APDs are arrayed, the width of the isolation portion is smaller than the width of the connecting portion.

Abstract: A photoelectric conversion apparatus includes a plurality of avalanche photodiodes. Each of the plurality of avalanche photodiodes includes an avalanche multiplication unit formed by a first semiconductor region of a first conductivity type that is arranged at a first depth, and a second semiconductor region of a second conductivity type different from the first conductivity type and which is arranged at a second depth deeper than the first depth. A fourth semiconductor region at least one of a conductivity type and an impurity concentration of which is different from those of a third semiconductor region of the second conductivity type is arranged at a position shallower than the third semiconductor region, and a depth of a boundary portion between the third semiconductor region and the fourth semiconductor region is deeper than that of the avalanche multiplication unit.