Contact resistance reduction to FinFET source/drain using dielectric dipole mitigated Schottky barrier height tuning

We demonstrate for the first time contact resistance reduction using dielectric dipole mitigated Schottky barrier height (SBH) tuning on a FinFET source/drain. Different techniques for forming a SiO₂/AlO_x dipole layer are investigated using diodes. FinFETs, with contacts containing a SBH tuning dipole layer, are also presented. Reduction of the SBH by 100meV from the AlO_x/SiO₂ dipole results in a 10Ω-μm² reduction in specific contact resistivity (ρ_CO) and a 100Ω-μm reduction in FinFET source/drain resistance (R_S/D). Larger reductions of ρ_CO should be possible if chemically formed or atomic-layer deposited SiO₂ is used in the dipole layer instead of interfacial SiO₂ due to the larger SBH reduction (ΔSBH ~300meV) obtained from these oxidation methods. Contact formation without the need for silicide makes this technique very promising for emerging devices, alternative channel materials, and sub-22nm CMOSFETS.