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 SiO
₂
/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
/SiO
₂
dipole results in a 10Ω-μm
²
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 SiO
₂
is used in the dipole layer instead of interfacial SiO
₂
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.