Patent ID: 8248502

Claim:
A method for making a photoelectric conversion device that includes a semiconductor substrate, a photoelectric conversion element and MOS transistors disposed on the semiconductor substrate, and a multilayer interconnection structure constituted by a plurality of wiring layers stacked with insulating films in between, the method comprising: forming a first insulating film on the semiconductor substrate; forming a first hole and a second hole in the first insulating film, the first hole exposing a plurality of active regions in the semiconductor substrate, a plurality of gate electrodes of the plurality of MOS transistors, or an active region and a gate electrode of a MOS transistor, and the second hole exposing one of the plurality of active regions; forming conductors in the first hole and the second hole to form a first plug in the first hole and a second plug in the second hole; forming a second insulating film on the first insulating film, the first plug, and the second plug, the second insulating film being contacted with the first insulating film; forming a third insulating film on the second insulating film; forming a first opening for a wiring of a dual damascene structure in the third insulating film while using the second insulating film as an etching stopper, the wiring serving as a bottommost layer of a multilayer interconnection structure; forming a second opening for the dual damascene structure, the second opening being formed as a via hole in the second insulating film and exposing the second plug; and forming conductors in the first opening and the second opening to form the dual damascene structure.