Feasible Integration Scheme for Dual Work Function FUSI/HfSiON Gate Stacks with Selective Metal Pile-up to nMOSFET

We propose a feasible integration scheme for dual FUSI/HfSiON CMOS with low work function metal pile-up to nMOSFET. A newly developed post phase change process to Ni
₃
Si and composition-dependent diffusivity of Al realize simplified integration of 4.3 eV/4.8 eV. Moreover, direct WF lowering of Pt
₂
Si with metal pile-up realizes 4.3 eV/4.9 eV.