CMOS Integration with Metal Gate and Doped High-K Oxides

A method and apparatus are described for fabricating single metal gate electrodes (35, 36) over a high-k gate dielectric layer (31, 32) that is separately doped in the PMOS and NMOS device areas (96, 97) by forming first capping oxide layer (23) with a first dopant species on a high-k gate dielectric layer (22) in at least the NMOS device area and also forming second capping oxide layer (27) with a second dopant species on a high-k gate dielectric layer (22) in at least the PMOS device area, where the first and second dopant species are diffused into the gate dielectric layer (22) to form a first fixed charge layer (31) in the PMOS device area of the high-k gate dielectric area and a second fixed charge layer (32) in the NMOS device area of the high-k gate dielectric area.