Work function tuning through dopant scanning and related effects in Ni fully silicided gate for sub-45nm nodes CMOS

A wide workfunction (/spl Phi//sub m/) tuning range from 4.29eV to 4.99eV using total silicidation of doped polysilicon gate with nickel is presented. As, B and P but also N, Ge, Sb, In and co-implants, have been investigated to modulate the NiSi gate workfunction by dopant pile up effect at the silicide/dielectric interface. For the first time, defectivity data on dual gate oxide are presented, in correlation with the activation annealing impact and back end of line (BEOL) thermal stress effects as well as thorough TEM observations.