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.