Work Function Adjustment and Polydepletion Reduction in Deep Partial and Full Silicidation of Poly-Si with Ni Layer

Dual work function metal gates fabricated by deep partial silicidation and full silicidation of Ni layer were investigated by both physical and electrical measurements. Deep partial and full silicidation as well as phase confirmation of Ni 2 Si and NiSi were studied by physical characterizations. Complementary metal oxid semiconductor work functions were extrapolated by electrical characterization and correlated with dopant accumulation caused by the snowplow effect during the silicidation. The polydepletion reductions were observed in both deep-partial and full silicidation of NiSi metal gates.