Semiconductor structure, electrode structure and method of forming the same

A semiconductor structure, comprising:

• a dielectric layer;
• a diffusion barrier layer disposed in the dielectric layer;
• a bottom electrode over the diffusion barrier layer;
• a magnetic tunneling junction (MTJ) layer over the bottom electrode;
• and
• a top electrode over the MTJ layer;
• wherein a top surface of the diffusion barrier layer is lower than a top surface of the dielectric layer, and a bottom surface of the bottom electrode in contact with the diffusion barrier layer is uneven, and a center region of the bottom surface of the bottom electrode is higher than an outer region of the bottom surface of the bottom electrode, and a top surface of the bottom electrode in contact with the MTJ layer is even.

A semiconductor structure, comprising:

• a dielectric layer;
• a diffusion barrier layer disposed in the dielectric layer;
• a protection layer over the dielectric layer;
• a bottom electrode over the diffusion barrier layer;
• and
• a magnetic tunneling junction (MTJ) layer over the bottom electrode;
• wherein a lower portion of the bottom electrode is disposed in the dielectric layer, and the MTJ layer and an upper portion of the bottom electrode is disposed in the protection layer, and the diffusion barrier layer and the lower portion of the bottom electrode are laterally in contact with the dielectric layer, and an interface formed by the dielectric layer and the protection layer is level with a bottom surface of the upper portion of the bottom electrode at regions neighboring the bottom surface of the upper portion of the bottom electrode.