Fluorine-free interface for semiconductor device performance gain

A semiconductor device, comprising:

• an active region;
• an epitaxial source/drain within and extending above the active region;
• an insulation layer adjacent to the active region;
• a plurality of dielectric layers that each reside above the insulation layer;
• a first layer stack residing above the active region and in one or more of the plurality of dielectric layers;
• and
• a second layer stack residing above the epitaxial source/drain and in the one or more of the plurality of dielectric layers,
• wherein each of the first layer stack and the second layer stack comprises:
• a first titanium layer residing on a bottom of each of the first layer stack and the second layer stack and on a portion of sides of each of the first layer stack and the second layer stack,
• a second titanium layer and a first metal layer that each reside on the first titanium layer,
• a second metal layer residing on the second titanium layer and the first metal layer, and
• a tungsten layer residing on the second metal layer.

A semiconductor device, comprising:

• an active region;
• an epitaxial source/drain within and extending above the active region;
• a first metal gate residing on at least a portion of the active region;
• an insulation layer adjacent to the active region;
• a plurality of dielectric layers that each reside above the insulation layer;
• a first layer stack residing on the first metal gate and in the plurality of dielectric layers;
• and
• a second layer stack, residing directly above and intersecting with the epitaxial source/drain, and residing in the plurality of dielectric layers,
• wherein each of the first layer stack and the second layer stack comprises:
• a material layer residing on a bottom of each of first layer stack and the second layer stack and on a portion of sides of each of the first layer stack and the second layer stack,
• a titanium layer and a metal layer residing on the material layer, and
• a metal layer residing on the titanium layer and the metal layer.