Semiconductor device
View Patent ↗A reliable semiconductor device having a multilayer wiring structure formed of copper as a main component material, which constrains occurrence of voids caused by stress migration. In the multilayer wiring structure, a first insulation layer having a high barrier property and a compression stress, and making contact with the upper surface of a first wiring made of copper as a main component material, a second insulation film having a tensile stress, and a third insulation film having a dielectric constant which is lower than those of the first and second insulation film, are laminated one upon another in the mentioned order as viewed the bottom thereof, and a via hole is formed piercing through the first insulation film, the second insulation film and the third insulation film, making contact with the first wiring.
1. A semiconductor device comprising:
a first wiring formed on a semiconductor substrate through the intermediary of an insulation film and made of copper as a main component material,
a first insulation film formed on the first wiring and having a barrier property against the copper of the first wiring, the first film having a compressive stress,
a second insulation film formed on the first insulation film, and having a tensile stress,
a third insulation film formed on the second insulation film, and having a tensile stress,
a via formed on the first wiring and piercing through the third to the first insulation films, and
a second wiring connected to the first wiring through the intermediary of the via,
wherein the third insulation film has a dielectric constant which is lower than those of the first and second insulation films.
2. A semiconductor device as set forth in claim 1 , wherein
the first insulation film has a film thickness which is less than that of the second insulation film.
3. A semiconductor device as set forth in claim 1 , wherein
the first insulation film has a Yong's modulus which is larger than that of the second insulation film, but the first insulation film has a film thickness which is less than that of the second insulation film.
4. A semiconductor device as set forth in claim 1 , wherein
the second insulation film has a barrier property which is higher than that of a silicon oxide film, against copper of the first wiring.
5. A semiconductor device as set forth in claim 1 , wherein
the first insulation film is formed of an insulation film containing at least nitrogen atoms.
6. A semiconductor device as set forth in claim 1 , wherein
the third insulation film is a low dielectric insulation film.
7. A semiconductor device as set forth in claim 1 , wherein
an layer made of copper at least a part of which is nitrated is interposed between the first wiring and the first insulation film.
8. A semiconductor device as set forth in claim 7 , wherein
the layer made of copper at least a part of which is nitrated, has a film thickness which is less than that of the first insulation film.
9. A semiconductor device as set forth in claim 1 , wherein a space is formed at least a part of the third insulation film.
10. A semiconductor device as set forth in claim 9 , wherein the space is adjacent to a side wall of the via.