High k metal gate stack with single work-function metal

An integrated circuit having an N-FET metal gate and a P-FET metal gate sharing the same work function metal, the integrated circuit comprising:

• an n-doped high dielectric constant material only along a bottom of a first opening in a dielectric layer, the n-doped high dielectric constant material is in direct contact with a portion of a substrate exposed at the bottom of the first opening;
• a p-doped high dielectric constant material only along a bottom of a second opening in the dielectric layer, the p-doped high dielectric constant material is in direct contact with a portion of the substrate exposed at the bottom of the second opening;
• a work function metal above and in direct contact with the p-doped high dielectric constant material and the n-doped high dielectric constant material;
• and
• a bulk fill material directly on top of the work function metal, wherein a width of the bulk fill material comprises more than about 30% of the width of each of the first opening and the second opening, wherein the work function metal is less than about 40 angstroms thick, and wherein the width of the first opening and the second opening are each less than 20 nanometers.

A integrated circuit comprising:

• an n-doped high-k dielectric layer conformally within a first opening in a dielectric layer such that the n-doped high-k dielectric layer is in direct contact with a portion of a substrate exposed at a bottom of the first opening;
• a p-doped high-k dielectric layer conformally within a second opening in the dielectric layer such that the p-doped high-k dielectric layer is in direct contact with a portion of the substrate exposed at a bottom of the second opening;
• a shared work function metal conformally within the first opening and the second opening above and in direct contact with both the p-doped high-k dielectric layer and the n-doped high-k dielectric layer;
• and
• a bulk fill material above and in direct contact with the shared work function metal.