Numerical simulation on novel FinFETs: asymmetric poly-silicon gate FinFETs and TiN gate FinFETs

We report our numerical study on the device performance of an asymmetric poly-silicon gate FinFET and FinFET with TiN metal gate structure. Our numerical simulation revealed that the asymmetric poly-silicon FinFET structure and TiN gate FinFET structures exhibit superior VT tolerance over the conventional FinFET structure with respect to the variation of fin thickness. For instance, the VT tolerance of the asymmetric poly-Si FinFET were 0.02 V while TiN gate FinFET exhibited 0.015 V tolerance for the variation of the fin thickness of 5 nm (from 30 to 35 nm) while the conventional FinFET demonstrates 0.12 V fluctuation for the same variation of the fin thickness. Our numerical simulation further revealed that the threshold voltage (VT) can be controlled within the range of −0.1∼+0.5 V through varying the doping concentration of the asymmetric poly-silicon gate region from 1.0×1018 to 1.0×1020 cm−3.