Design of Bulk Fin-Type Field-Effect Transistor Considering Gate Work-Function

We proposed a new body-tied triple-gate fin-type field-effect transistor (bulk FinFET) which has different gate work-functions on the top- and side-channel regions. The effect of gate work-function on the characteristics of the bulk FinFETs was studied by using three-dimensional device simulator. By increasing the top-gate work-function (Φ_TG) at a fixed side-gate work-function (Φ_SG) of the bulk FinFET, threshold voltage (V_th) increases and off-state leakage current (I_off) reduces significantly without increasing doping concentration of the fin body. The bulk FinFETs with the low body doping and the threshold voltage controlled by midgap-gate work-function shown very small dependence on the corner shape, but shown very poor short channel effect (SCE). It was also shown that devices with the V_th controlled by body doping shows significant corner effect and the effect becomes small as the fin width decreases. By applying our approach, we could reduce the off-current by more than 10 times without increasing fin body doping concentration.