Body-Tied Germanium FinFETs Directly on a Silicon Substrate

摘要

We fabricated body-tied Ge p-channel fin field-effect transistors (p-FinFETs) directly on a Si substrate with a high-$kappa$/metal gate stack. This scheme is fully compatible with Si standard processing. The FinFET structure has excellent control on the channel potential and thus can improve the short-channel effect. The diode with $hbox{p}^{+}hbox{-Ge-Si}$ heterojunctions illustrates a remarkably high $I_{rm ON}/I_{rm OFF} > hbox{10}^{6}$ despite the presence of misfit dislocations at the interface. The high-hole-mobility body-tied Ge p-FinFETs with a fin width $W_{rm Fin}$ of $sim$40 nm and a mask channel length $L_{rm Mask}$ of 120 nm depict a driving current of 22 $muhbox{A}/muhbox{m}$ at $V_{G} = -hbox{2} hbox{V}$ and a low off-current of 3 $hbox{nA}/muhbox{m}$ at $V_{G} = hbox{2} hbox{V}$. The subthreshold characteristics with a swing of 228 mV/dec and drain-induced barrier lowering of 288 mV/V are demonstrated.