A complementary metal oxide semiconductor (CMOS) structure including a scaled n-channel field effect transistor (nFET) and a scaled p-channel field transistor (pFET) which do not exhibit an increased threshold voltage and reduced mobility during operation is provided Such a structure is provided by forming a plasma nitrided, nFET threshold voltage adjusted high k gate dielectric layer portion within an nFET gate stack, and forming at least a pFET threshold voltage adjusted high k gate dielectric layer portion within a pFET gate stack. In some embodiments, the pFET threshold voltage adjusted high k gate dielectric layer portion in the pFET gate stack is also plasma nitrided. The plasma nitrided, nFET threshold voltage adjusted high k gate dielectric layer portion includes up to 15 atomic % N2 and an nFET threshold voltage adjusted species located therein, while the plasma nitrided, pFET threshold voltage adjusted high k gate dielectric layer portion includes up to 15 atomic % N2 and a pFET threshold voltage adjusted species located therein.