We investigated the impact of fin length (Tfin) on the threshold voltage (Vth) modulation by back bias (Vb) for independent double-gate (IDG) tunnel fin field-effect transistors (tFinFETs). It was found that Vth can be tuned by Vb for IDG tFinFETs regardless of Tfin, which can be explained by the back-gate-effect model of IDG FinFETs. For IDG tFinFETs, the slope (back-gate-effect factor (γ)) of Vth with respect to Vb increases with thinning Tfin. This means that Tfin thinning is effective for tuning Vth by Vb for IDG tFinFETs. Furthermore, it was demonstrated that this back-bias-effect is consistent with the results of device simulation using an advanced nonlocal band-to-band model.
- Back bias
- Threshold voltage
- Tunnel field-effect transistor (FET)