An interconnection wiring system incorporating two levels of interconnection wiring separated by a first dielectric, a capacitor formed by a second dielectric, a bottom electrode of the lower interconnection wiring or a via and a top electrode of the upper interconnection wiring or a separate metal layer. The invention overcomes the problem of leakage current and of substrate stray capacitance by positioning the capacitor between two levels of interconnection wiring.
A thin lower electrode layer having an optimally protected capacitor dielectric is produced and structured. A conventional metallization layer for strip conductors is placed thereon as an upper electrode and structured. The capacitor dielectric can be deposited on a very even, preferably metallic surface (e.g. preferably TiN), sealed by a thin, preferably metallic layer (e.g. TiN) and protected so that is does not become thinned or damaged by other process steps.
A lower interconnection is provided on a semiconductor substrate. A MIM capacitive element is provided on a first interlayer insulation film in which the lower interconnection is buried, and includes a lower electrode, an upper electrode, and a dielectric film sandwiched therebetween. An upper interconnection is provided on a second interlayer insulation film in which the MIM capacitive element is buried. A contact electrically connects the lower electrode and the upper interconnection. The lower electrode is mainly formed of Al, so that they are lower in electrical resistance than barrier metal, and also low in stress value. Therefore, it becomes possible to widen the area of the lower electrode for electrically connecting the contact while restraining their influences on charge accumulation and close contact between the lower electrode and the insulation film. In addition, since the electrical resistance is lowered, the thickness of the lower electrode can be increased. Accordingly, the MIM capacitive element with a large capacitance can be manufactured with a high yield.
A method for manufacturing a semiconductor device is provided. The method includes forming a lower interconnection on a semiconductor substrate; forming a first interlayer insulation film in which the lower interconnection is buried; forming an MIM capacitive element on the first interlayer insulation film, the MIM capacitive element being formed by layering a lower electrode, a dielectric film, and an upper electrode; forming a second interlayer insulation film in which the MIM capacitive element is buried; forming via holes in the second interlayer insulation film so as to reach the lower electrode; forming a connection plug by filling the via hole with conductive film; and forming an upper interconnection to be connected to the connection plug above the second interlayer insulation film.
