Patent ID: 7393715

Claim:
A method of manufacturing an image pickup device that includes: an image pickup area having plural photoelectric conversion elements arranged in a semiconductor substrate and transistors for transferring electrical signals from the photoelectric conversion elements, and a multi-layer wiring structure arranged above the semiconductor substrate and having wiring layers each having a wiring, plural interlayer insulation films arranged between the wiring layers and between the image pickup area and a wiring layer, and plural buried plugs arranged penetrating respective ones of the interlayer insulation films for electrically connecting wirings mutually adjacent in a direction of lamination or a wiring and a part of the image pickup area, wherein the method comprises: forming the buried plugs, which includes steps of, for each interlayer insulation film in which a buried plug is to be formed: forming a connecting hole in the interlayer insulation film; depositing a metal layer on the interlayer insulation film, so as to bury an interior of the connecting hole and to cover at least a part of an upper surface of the interlayer insulation film in a laminating direction thereof; and removing at least a part of the metal layer on the upper surface of the interlayer insulation film to form the buried plug, wherein the step of removing at least a part of the metal layer is executed by an etch-back method on a buried plug in at least one uppermost interlayer insulation film in the laminating direction and by a chemical mechanical polishing method on a buried plug in an interlayer insulation film different from the at least one uppermost interlayer insulation film.