Independent double-gate FinFETs with asymmetric gate stacks

摘要

Flexibly controllable threshold voltage (V_(th)) asymmetric gate oxide thickness (T_(ox)) independent double-gate (DG) FinFETs (4T-FinFETs) have been demonstrated. Thin drive-gate oxide (HfO_2 or SiON or SiO_2) and slightly thick V_(th)-control-gate oxide (thick SiO_2+drive-gate oxide) have been successfully incorporated into the 4T-FinFETs by utilizing the ion-bombardment-enhanced etching of SiO_2. It was experimentally confirmed that, all the asymmetric T_(ox) 4T-FinFETs give the significantly improved subthreshold slope and thus gain higher on-current as compared to the symmetric one. Simulation results showed that the asymmetric T_(ox) 4T-FinFETs are advantageous even in 20-nm-gate-length region.