High-k gate dielectrics (HK), such as HfO2 or HfSiON, are being considered as the gate dielectric option for the 45nm node and beyond. In order to alleviate the Fermi-level pinning issue and to enhance the CET (Capacitive Effective Thickness) by generating the depletion layer in poly-Silicon gate, metal gate electrodes with proper work functions (WF) have to be used on the high-k dielectrics.