Combinatorial study of Ni–Ti–Pt ternary metal gate electrodes on $HfO2$ for the advanced gate stack

The authors have fabricated combinatorial Ni–Ti–Pt ternary metal gate thin film libraries on $HfO2$ using magnetron co-sputtering to investigate flatband voltage shift $(ΔVfb)$⁠, work function $(Φm)$⁠, and leakage current density $(JL)$ variations. A more negative $ΔVfb$ is observed close to the Ti-rich corner than at the Ni- and Pt-rich corners, implying smaller $Φm$ near the Ti-rich corners and higher $Φm$ near the Ni- and Pt-rich corners. In addition, measured $JL$ values can be explained consistently with the observed $Φm$ variations. Combinatorial methodologies prove to be useful in surveying the large compositional space of ternary alloy metal gate electrode systems.