Conductive structures and methods of forming the same

A method, comprising:

• forming a plurality of recesses in at least one dielectric layer and adjacent to a source/drain structure;
• forming a seed layer within the recesses using conformal chemical vapor deposition (CVD) with a precursor selected from a ruthenium dodecacarbonyl, a molybdenum chloride, a tungsten fluoride, or a combination thereof;
• etching the seed layer from part of sidewalls of the recesses, wherein remaining portions of the seed layer are over bottom surfaces of the recesses;
• and
• forming gate vias within the recesses and over the remaining seed layer,
• wherein a first recess of the plurality of recesses exposes a portion of a top surface of a first gate structure,
• wherein a second recess of the plurality of recesses exposes a portion of a top surface of a second gate structure,
• wherein the first recess and the second recess are formed through an etch stop layer (ESL) that is on the top surface of the first gate structure and the top surface of the second gate structure,
• wherein top surfaces of the remaining portions of the seed layer are higher than a top surface of the ESL, and
• wherein portions of the ESL are on side surfaces of the remaining portions of the seed layer.

A method, comprising:

• forming a gate structure adjacent to a source/drain structure;
• forming a seed layer over the gate structure;
• and
• forming a gate via over the seed layer and electrically connected to the gate structure through the seed layer,
• wherein a bottom surface of the gate via has a width approximately equal to a width of a top surface of the seed layer, and the top surface of the seed layer is level with the bottom surface of the gate via,
• wherein the seed layer is formed through an etch stop layer (ESL) that is on a top surface of the gate structure,
• wherein a top surface of the seed layer is higher than a top surface of the ESL, and
• wherein a portion of the ESL is on a side surface of the seed layer.