Negative Capacitance FinFET With Sub-20-mV/decade Subthreshold Slope and Minimal Hysteresis of 0.48 V

In this letter, an n-type short-channel negative capacitance FinFET (NC-FinFET) with a hysteresis window of 0.48 V, an on-/off-current ratio of 10
⁷
, and a sub-20-mV/decade average subthreshold slope (SS
_avg
) that is intended to overcome the Boltzmann limit (i.e., the physical limit in the SS, which is 60 mV/decade at 300 K), is experimentally demonstrated vs. a baseline FinFET with an SS
_avg
of ~105 mV/decade. In our testing, we confirmed that the large hysteresis window in a short-channel NC-FinFET can be suppressed by using an appropriate source/drain extension length (
$\text {L}_{\text {ext}})$
. As
$\text {L}_{\text {ext}}$
in the NC-FinFET is increased, the gate-to-source/drain capacitance (
$\text {C}_{\text {GS}}/\text {C}_{\text {GD}})$
decreased and the hysteresis window narrows.