Semiconductor devices and methods of fabricating the same

A method, comprising:

• forming a dielectric layer over a semiconductor substrate;
• forming a contact opening in the dielectric layer;
• performing a directional deposition process to form a first metal layer in the contact opening;
• performing a directional treatment process of the first metal layer to form a barrier layer;
• depositing a seed layer over the barrier layer;
• removing portions of the seed layer and the first metal layer from a sidewall surface of the contact opening to expose the dielectric layer;
• and
• depositing a second metal layer over remaining portions of the seed layer, the barrier layer, and the first metal layer over a bottom surface of the contact opening.

The method of claim 10, comprising:

• forming a source/drain feature adjacent a channel region and over a semiconductor substrate;
• and
• planarizing the second metal layer to form a source/drain contact,
• wherein the performing of the directional deposition process includes implementing a plasma deposition of a metal precursor 12. The method of claim 11, wherein the plasma deposition is implemented at an elevated temperature capable of causing the first metal layer to react with the source/drain feature to form a silicide layer over the bottom surface of the contact opening.

A semiconductor structure, comprising:

• a dielectric layer;
• a silicide layer;
• a barrier layer over the silicide layer;
• a seed layer over the barrier layer;
• and
• a metal layer between a sidewall of the seed layer and a sidewall of the dielectric layer, a sidewall of each of the silicide layer, the barrier layer, and the metal layer directly contacting the sidewall of the dielectric layer.