A composite semiconductor device includes a substrate; a plurality of circuits formed on the substrate; one or more wiring layers each including a plurality of wiring patterns connected to circuits of the plurality of circuits, a plurality of dummy patterns electrically isolated from the plurality of circuits, and an interlayer dielectric film that is spin-coated directly onto the wiring patterns and onto the dummy patterns, and that is a spin-coated layer, the dummy patterns being formed in areas where the wiring patterns are absent and lying substantially in a plane in which the wiring patterns lie; and a semiconductor thin film layer including semiconductor device elements and disposed on an upper most surface of the one or more wiring layers. The spin-coated layer may be formed of an organic material or an oxide material.