Semiconductor device

A semiconductor device comprising:

• a lower structure;
• a first electrode on the lower structure;
• a second electrode on the first electrode;
• and
• a dielectric layer between the first electrode and the second electrode,
• wherein the first electrode includes a first region including at least a titanium (Ti) element, a niobium (Nb) element, and a nitrogen (N) element, and
• in the first region of the first electrode, a concentration of the Nb element gradually increases in a horizontal direction, away from a side surface of the first electrode.

A semiconductor device comprising:

• a lower structure;
• a first electrode on the lower structure;
• a second electrode on the first electrode;
• and
• a dielectric layer between the first electrode and the second electrode,
• wherein the first electrode includes a first region including at least three elements,
• the first region of the first electrode includes a first sub-region and a second sub-region, wherein the first sub-region is between, in a horizontal direction, the second sub-region and a side surface of the first electrode,
• the first sub-region includes first layers and second layers alternately stacked in the horizontal direction,
• the second sub-region includes third layers and fourth layers alternately stacked in the horizontal direction,
• the first layers and the third layers include a same first material,
• the second layers and the fourth layers include a same second material, and
• a horizontal thickness of each of the second layers is smaller than a horizontal thickness of each of the fourth layers.