Patent ID: 8283755

Claim:
A multichip semiconductor device including a plurality of chips stacked on each other, each of the chips having a semiconductor substrate on which circuit components are formed, wherein two adjacent chips included in the plurality of chips are electrically connected to each other via a connecting substrate provided between the two adjacent chips, wherein each of the two adjacent chips comprises: a first interlayer insulating film formed above a surface of the semiconductor substrate; a through hole passing through the semiconductor substrate and the first interlayer insulating film; a conductive plug formed entirely within the through hole; a second interlayer insulating film formed on the first interlayer insulating film; and a metal interconnection which passes through the second interlayer insulating film and which connects to a portion of the conductive plug, an area of the portion being smaller than a cross-sectional area of the conductive plug; and the conductive plugs of the two adjacent chips are electrically connected to each other via the connecting substrate.