Semiconductor device capable of reducing interelectrode leak current and manufacturing method thereof

1. A semiconductor device having a capacitive structure formed by layering a lower electrode, a capacitive insulation film, and an upper electrode in order on a wiring or conductive plug, the semiconductor device comprising, as the capacitive structure, a thin-film capacitor having a lower electrode structure comprising:

a polycrystalline film; and

an amorphous or microcrystalline film formed on the polycrystalline film or a laminate of amorphous and microcrystalline films formed on the polycrystalline film,

wherein the upper electrode is smaller in dimension than the lower electrode structure in the thin-film capacitor,

wherein the semiconductor device further comprises a first hard mask film which covers only the upper electrode,

a second hard mask film which covers the first hard mask film and side surfaces of the upper electrode and the first hard mask film, and

the capacitive insulation film has a capacitance per unit area between 3 fF/μm 2 and 25 fF/μm 2 .

2. The semiconductor device according to claim 1 , wherein the amorphous or microcrystalline film in the lower electrode structure of the thin-film capacitor has a layered structure composed of two or more layers.

3. The semiconductor device according to claim 2 , wherein the polycrystalline film of the thin-film capacitor has a greater thickness than that of the amorphous or microcrystalline film or the laminate structure thereof.

4. The semiconductor device according to claim 1 , wherein the magnitude of roughness of the surface of the lower electrode structure of the thin-film capacitor is equal to or less than the thickness of the capacitive insulation film.

5. The semiconductor device according to claim 1 , wherein the amorphous or microcrystalline film in the thin-film capacitor is a tantalum film.

6. The semiconductor device according to claim 1 , wherein the amorphous or microcrystalline film in the thin-film capacitor is a nitrogen-containing tantalum film or a tantalum nitride film.

7. The semiconductor device according to claim 1 , wherein the polycrystalline film in the thin-film capacitor is a titanium nitride film.

8. The semiconductor device according to claim 1 , wherein the upper electrode in the thin-film capacitor is a titanium nitride film.

9. The semiconductor device according to claim 1 , wherein the capacitive insulation film in the thin-film capacitor is a silicon nitride film or a film primarily composed of silicon nitride.

10. A semiconductor device having a multilayer wiring structure, comprising the thin-film capacitor according to claim 1 formed between a power supply line and a ground line in the multilayer wiring structure.

11. The semiconductor device according to claim 10 , wherein an interlayer insulation film forming at least one layer of the multilayer wiring structure contains an insulation material having a permittivity of 3.0 or less.

12. A semiconductor device having a multilayer wiring structure, comprising the thin-film capacitor according to claim 1 arranged between any wiring layers vertically adjacent to each other.

13. The semiconductor device according to claim 12 , wherein an interlayer insulation film forming at least one layer of the multilayer wiring structure contains an insulation material having a permittivity of 3.0 or less.

14. The semiconductor device according to claim 12 , wherein a wiring composed primarily of aluminum is formed in an uppermost layer, and a multilayer copper wiring is formed in the lower layer thereof.

15. The semiconductor device according to claim 14 , wherein an interlayer insulation film forming at least one layer of the multilayer wiring structure contains an insulation material having a permittivity of 3.0 or less.