Semiconductor device

A semiconductor device, comprising:

• a first unit;
• a second unit, wherein the first and second units are bonded together, and wherein:
• the first unit comprises:
• a first wiring layer including:
• a first interlayer insulating film;
• at least one first electrode pad;
• and
• a plurality of first dummy electrodes,
• wherein the at least one first electrode pad is embedded in the first interlayer insulating film and has one planar surface located on a same plane as a planar first bonding surface of the first interlayer insulating film,
• wherein each of the first dummy electrodes is embedded in the first interlayer insulating film,
• wherein each of the first dummy electrodes has one planar surface located on the same plane as the planar first bonding surface of the first interlayer insulating film,
• wherein the planar surfaces of the first dummy electrodes are distributed over the first bonding surface,
• wherein at least some of the first dummy electrodes are disposed adjacent the at least one first electrode pad, and
• wherein a first one of the first dummy electrodes and a second one of the first dummy electrodes are a first distance from an edge of the at least one first electrode pad;
• and
• the second unit comprises:
• a photoelectric conversion element;
• and
• a second wiring layer including:
• a second interlayer insulating film,
• at least one second electrode pad, and
• a plurality of second dummy electrodes,
• wherein the at least one second electrode pad is embedded in the second interlayer insulating film and has one planar surface located on a same plane as a planar second bonding surface of the second interlayer insulating film that faces the first bonding surface of the first interlayer insulating film,
• wherein at least a portion of the one planar surface of the at least one second electrode pad is bonded to at least a portion of the one planar surface of the at least one first electrode pad, at least a portion of the planar surface of one of the first dummy electrodes, or both,
• wherein each of the second dummy electrodes is embedded in the second interlayer insulating film,
• wherein each of the second dummy electrodes has one planar surface located on the same plane as the planar second bonding surface of the second interlayer insulating film,
• wherein the planar surfaces of the second dummy electrodes are distributed over the second bonding surface,
• wherein at least some of the second dummy electrodes are disposed adjacent to the at least one second electrode pad, and are bonded to the first dummy electrodes, to the at least one first electrode pad, or both,
• wherein the at least one first electrode pad is disposed plane-symmetrically to the at least one second electrode pad with respect to a plane between the first and second units and parallel to the first and second bonding surfaces,
• wherein the first dummy electrodes are disposed plane-symmetrically to the second dummy electrodes with respect to a plane between the first unit and the second unit and parallel to the first and second bonding surfaces,
• wherein all surfaces of the first dummy electrodes except for the one planar surface located on the same plane as the first bonding surface of the first interlayer insulating film are entirely in contact with the first interlayer insulating film,
• wherein all surfaces of the second dummy electrodes except for the one planar surface located on the same plane as the second bonding surface of the second interlayer insulating film are entirely in contact with the second interlayer insulating film, and
• wherein the planar surface of at least one of the second dummy electrodes contacts the planar surfaces of two of the first dummy electrodes and a portion of the planar surface of the first interlayer insulating film between the two of the first dummy electrodes.