Demonstration of Asymmetric Gate Oxide Thickness 4-Terminal FinFETs

Flexibly-V
_th
-controllable four-terminal-FinFETs (4T-FinFETs) (Fried, et al., 2003) have great potential to prevent catastrophic increases in static power consumption. Previously-reported 4T-FinFETs had symmetrically thin gate oxides on both channels, unfortunately resulting in large S-slope due to the negative effect of the high second gate (G2) controllability (Lim, et al., 1983). To attain a good S-slope even after DG separation, the asymmetric gate oxide thickness (T
_ox
) (thin drive-gate oxide and slightly thick V
_th
-control-gate oxide) have been suggested. (Wong, et al., 1998) This paper demonstrates, for the first time, asymmetric-T
_ox
4T-FinFETs with HfO
₂
(EOT=1.4nm) for one side and HfO
₂
+thick SiO
₂
(EOT=6.4-9.4nm) for the other side fabricated by using a novel ion-bombardment-enhanced etching (IBEE) process