High performance MOSFET

A semiconductor structure comprising:

• a Si-containing semiconductor substrate having at least one trench isolation region located therein;
• an epitaxial Si layer abutting a surface of said Si-containing semiconductor substrate;
• at least one gate stack comprising, from bottom to top, a gate dielectric, a metal gate electrode portion and a polysilicon electrode portion, located on a portion of said epitaxial Si layer;
• and
• a well region of a first conductivity type located beneath the epitaxial Si layer, a well region of a first conductivity type located beneath the epitaxial semiconductor layer, wherein the well region has a central portion and two horizontally abutting end portions, said central portion having a higher concentration of a first conductivity type dopant than the two horizontally abutting end portions, and where each of said two end portions has an outer edge that is in contact with a source/drain diffusion region of a second conductivity type which differs from that of the first conductivity type and where said central portion is located beneath the at least one gate stack and does not extend beyond vertical sidewalls of said at least one gate stack, and wherein a portion of both of the two horizontal abutting end portions extends under the at least one gate stack.