Semiconductor device

1 . A semiconductor device comprising:

a lower structure;

a plurality of lower electrodes on the lower structure;

an upper electrode on the plurality of lower electrodes;

a dielectric layer between the plurality of lower electrodes and the upper electrode, and including a ferroelectric layer or an antiferroelectric layer; and

a plurality of interfacial layers between the plurality of lower electrodes and the dielectric layer,

wherein the plurality of interfacial layers includes:

a first layer contacting the plurality of lower electrodes, and including a first metal element, a second metal element, different from the first metal element, and elemental nitrogen; and

a second layer between the first layer and the dielectric layer, and including the first metal element, the second metal element, and elemental oxygen, and

wherein a concentration of the second metal element in the first layer is lower than a concentration of the second metal element in the second layer.

2 . The semiconductor device of claim 1 , wherein a concentration of the first metal element in the first layer is higher than a concentration of the first metal element in the second layer.

3 . The semiconductor device of claim 1 , wherein a first thickness of the first layer is greater than a second thickness of the second layer.

4 . The semiconductor device of claim 3 , wherein the first thickness is in a range from about 1 angstrom (Å) to 20 angstroms (Å), and

the second thickness is in a range from about 1 angstrom (Å) to 10 angstroms (Å).

5 . The semiconductor device of claim 1 , further comprising a support layer contacting the plurality of lower electrodes and extending in a direction, parallel to an upper surface of the lower structure,

wherein upper and lower surfaces of the support layer are in contact with the dielectric layer.

6 . The semiconductor device of claim 5 , wherein the first layer is free of having an overlap with the support layer in a vertical direction perpendicular to the upper surface of the lower structure, and

the second layer overlaps the support layer in the vertical direction.

7 . The semiconductor device of claim 5 , wherein the first layer extends on a side surface of the second layer and a portion of a side surface of the support layer.

8 . The semiconductor device of claim 5 , wherein the second layer comprises a portion having a narrower width than other portions of the second layer toward the support layer.

9 . The semiconductor device of claim 5 , wherein the first layer includes a convex shape portion in a direction from the second layer toward the plurality of lower electrodes, and

the second layer comprises a convex shape portion in a direction from the first layer toward the dielectric layer.

10 . The semiconductor device of claim 5 , wherein the plurality of interfacial layers further comprise a third layer disposed between the first layer and the second layer,

wherein the third layer comprises the first metal element, the second metal element, elemental nitrogen, and elemental oxygen.

11 . The semiconductor device of claim 10 , wherein, in a vertical direction perpendicular to the upper surface of the lower structure, a portion of the third layer overlaps the support layer.

12 . The semiconductor device of claim 1 , further comprising:

a support layer contacting the plurality of lower electrodes and extending in a direction, parallel to an upper surface of the lower structure; and

a dummy interfacial layer between the support layer and the dielectric layer,

wherein the dummy interfacial layer includes the second metal element, and

a ratio of an amount of the second metal element per unit in the plurality of interfacial layers relative to an amount of the second metal element per unit in the dummy interfacial layer is about 1000 to about 10000.