Body-Tied Germanium FinFETs Directly on a Silicon Substrate

We fabricated body-tied Ge p-channel fin field-effect transistors (p-FinFETs) directly on a Si substrate with a high-κ/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 p⁺-Ge/n-Si heterojunctions illustrates a remarkably high I_ON/I_OFF >; 10⁶ despite the presence of misfit dislocations at the interface. The high-hole-mobility body-tied Ge p-FinFETs with a fin width W_Fin of ~ 40 nm and a mask channel length L_Mask of 120 nm depict a driving current of 22 μA/μm at VG = -2V and a low off-current of 3 nA/μm at VG = 2V. The subthreshold characteristics with a swing of 228 mV/dec and drain-induced barrier lowering of 288 mV/V are demonstrated.