Junctionless Gate-all-around pFETs on Si with In-situ doped Ge channel

High performance junctionless Ge Gate-all-around pFETs with fin width down to 9 nm are demonstrated. The device with the L_eff of 250 nm and channel doping of 8×10 cm- has I_on/I_off= 1×10, SS = 95 mV/dec, and I_on = 390 μA/μm. The gate controllability can be further improved with low EOT gate stack of ~ 0.7 nm for the SS down to 84 mV/dec. Junctionless devices also show higher mobility at the large V_Gs - V_t region than the inversion mode devices due to less dependence on surface roughness scattering. The configuration of fin width and channel concentration to achieve low SS is investigated.