High-Performance Germanium $\Omega$ -Gate MuGFET With Schottky-Barrier Nickel Germanide Source/Drain and Low-Temperature Disilane-Passivated Gate Stack

We report high-performance p-channel Ω-gate germanium (Ge) p-channel multigate field-effect transistor (MuGFET) with low-temperature Si₂H₆ surface passivation and Schottky-barrier nickel germanide (NiGe) metallic source/drain, fabricated on high-quality germanium-on-insulator (GeOI) substrates using sub-400°C process modules. As compared with other reported p-channel multigate Ge devices formed by top-down approaches, the Ge MuGFETs in this letter have a record-high ON-state current I_ON of ~450 μA/μm at V_GS - V_TH = -1 V and V_DS = - 1 V. High peak intrinsic saturation transconductance of ~740 μS/μm and low OFF-state current are reported. We also study the effect of fin or channel doping on Ge MuGFET performance. The simple MuGFET process developed using GeOI substrate would be a good reference for future 3-D Ge device fabrication.