Semiconductor device and method for manufacturing the same
View Patent ↗In order to achieve the reduction of contact resistance by forming a metal silicide layer with a sufficient thickness in an interface between a polycrystalline silicon plug and an upper conductive plug, the polycrystalline silicon plug contains germanium, which is ion-implanted before forming the metal silicide layer.
1. A semiconductor device, comprising:
an insulating film overlaying a surface of a substrate; and
a plug structure disposed in a hole formed in the insulating film, the plug structure comprising
a first conductor including a polycrystalline silicon containing germanium,
metal silicide formed on a surface of the first conductor, and
a second conductor contacting the metal silicide,
wherein the second conductor comprises a barrier metal film and a metal plug, the barrier metal film contacting a bottom surface and opposing side surfaces of the metal plug.
2. The semiconductor device according to claim 1 , wherein the first conductor is implanted with germanium ion with a dose of 1×10 14 to 1×10 16 atoms/cm 2 .
3. The semiconductor device according to claim 1 , wherein the metal plug is a tungsten plug.
4. The semiconductor device according to claim 3 , further comprising:
a capacitor connected to the plug structure.
5. The semiconductor device according to claim 1 , wherein the plug structure is connected to one electrode of a semiconductor element formed on the substrate.
6. The semiconductor device according to claim 5 , wherein the semiconductor element is an embedded gate type transistor in which a gate electrode is embedded into a semiconductor substrate, and the plug structure is connected to a diffusion layer formed on the surface of the semiconductor substrate as an electrode of the transistor.
7. The semiconductor device according to claim 6 , further comprising:
a bit line connected to another diffusion layer, which is different from the diffusion layer connected to the plug structure, on the semiconductor substrate,
wherein the upper surface of the plug structure is formed on the same face as the upper surface of an insulating film on the bit line provided into the insulating film.
8. The semiconductor device according to claim 5 , wherein the semiconductor element is a transistor having a structure that at least a part of a gate electrode is projected onto a semiconductor substrate, and the plug structure is connected to a diffusion layer formed on the surface of the semiconductor substrate as an electrode of the transistor.
9. A semiconductor device, comprising:
an insulating film overlaying a surface of a substrate; and
a plug structure disposed in a hole formed in the insulating film, the plug structure comprising
a first conductor, metal silicide, and a second conductor, in order, from a side close to the surface of the substrate,
the first conductor containing germanium, and
the second conductor comprising a barrier metal film and a metal plug, the barrier metal film contacting a bottom surface and opposing side surfaces of the metal plug.
10. The semiconductor device according to claim 9 , wherein the first conductor is implanted with germanium ion with a dose of 1×10 14 to 1×10 16 atoms/cm 2 .