Patent ID: 7541650

Claim:
An integrated circuit comprising: at least a first field effect transistor of a first conductivity type having a first dopant profile and a gate stack comprising a dielectric layer, a first metal region over the dielectric layer and a second metal region over the first metal region; and at least a second field effect transistor of the first conductivity type having a second dopant profile and a gate stack comprising a dielectric layer, a first metal region over the dielectric layer and a second metal region over the first metal region, wherein the first dopant profile and second dopant profile are substantially the same, the composition of the gate stacks of the first and second transistors is the same, the thickness of the second metal region of the first and second field effect transistors is substantially the same and the thickness of the first metal region of the first field effect transistor is different than the thickness of the first metal region of the second field effect transistor and the work function of gate stack of the first field effect transistor differs from the work function of the second field effect transistor by at least about 20%.