Capacitors and semiconductor devices including the same

1. A capacitor, comprising:

a lower electrode having a curved surface;

a first seed on a sidewall of the lower electrode, the first seed including a metal silicide and having a shape corresponding to the curved surface of the lower electrode;

a dielectric layer on the lower electrode, the dielectric layer covering the first seed; and

an upper electrode on the dielectric layer,

wherein the lower electrode is in contact with a first curved surface of the first seed and the dielectric layer is in contact with a second curved surface of the first seed, the first curved surface being opposite the second curved surface.

2. The capacitor as claimed in claim 1 , wherein the first seed has a grain shape.

3. The capacitor as claimed in claim 1 , further comprising:

a substrate having the lower electrode thereon;

an insulating interlayer between the substrate and the lower electrode; and

a plug extending through the insulating interlayer to electrically connect the substrate and the lower electrode.

4. The capacitor as claimed in claim 3 , further comprising a second seed between the plug and the lower electrode, the second seed including a second metal silicide and having a grain shape.

5. The capacitor as claimed in claim 3 , further comprising a seed layer pattern between the plug and the lower electrode.

6. A semiconductor device, comprising:

a transistor including a gate structure and an impurity region, the gate structure being on a substrate, the impurity region being at an upper portion of the substrate and being adjacent to the gate structure;

a plug electrically connected to the impurity region through an insulating interlayer, the insulating interlayer being on the substrate and covering the transistor; and

a capacitor as claimed in claim 1 .

7. The semiconductor device as claimed in claim 6 , further comprising a second seed between the plug and the lower electrode, the second seed including a second metal silicide and having a grain shape.

8. A capacitor, comprising:

a lower electrode, a bottom surface and a sidewall of the lower electrode having a plurality of protrusions thereon;

first seeds adjacent to the sidewall of the lower electrode and second seeds adjacent to the bottom surface of the lower electrode, the first and second seeds having a shape corresponding to the protrusions;

a dielectric layer on the lower electrode, the dielectric layer covering the second seeds; and

an upper electrode on the lower electrode,

wherein the lower electrode is in contact with first curved surfaces of the first seeds and the dielectric layer is in contact with second curved surfaces of the first seeds, the first curved surfaces being opposite the second curved surfaces.

9. The capacitor as claimed in claim 8 , wherein the dielectric layer contacts the first seeds, and the dielectric layer is directly between the first seeds and the upper electrode.

10. The capacitor as claimed in claim 8 , wherein the dielectric layer has a plurality of second protrusions therein, a shape of the second protrusions corresponding to the shape of the first seeds.

11. The capacitor as claimed in claim 8 , wherein the lower electrode, the dielectric layer, and the upper electrode have uneven surfaces based on an arrangement of the first and second seeds.