Semiconductor structure, electrode structure and method of forming the same

An electrode structure, comprising:

• a metal layer;
• a dielectric layer over the metal layer;
• a diffusion barrier layer disposed in the dielectric layer, wherein the diffusion barrier layer is over and coupled to the metal layer;
• and
• a first deposition of electrode material over the diffusion barrier layer;
• a second deposition of electrode material over the first deposition of electrode material;
• wherein the diffusion barrier layer and the first deposition of electrode material are laterally in contact with the dielectric layer, the first deposition of electrode material spacing the diffusion harrier layer and the second deposition of electrode material apart;
• and
• a top surface of the diffusion barrier layer is uneven and a center region of the top surface is higher than an outer region of the top surface.

An electrode structure, comprising:

• a metal layer;
• a dielectric layer over the metal layer;
• a diffusion barrier layer over and coupled to the metal layer;
• and
• a protection layer over the dielectric layer;
• a bottom electrode over the diffusion barrier layer;
• wherein a lower portion of the bottom electrode and the diffusion barrier layer are disposed in the dielectric layer and laterally in contact with the dielectric layer, and an upper portion of the bottom electrode is disposed in the protection layer and laterally in contact with the protection layer;
• and
• a top surface of the diffusion barrier layer is uneven and a center region of the top surface is higher than an outer region of the top surface.