Vertically Stacked Nanosheets Tree-Type Reconfigurable Transistor With Improved ON-Current

In this article, a novel tree-type channel reconfigurable field-effect transistor (RFET) is proposed to obtain improved ON-state performance. Compared with the conventional nanosheet (NS) channel structure, an additional interbridge (IB) channel is vertically intersected in tree-type RFET. Geometry parameters of IB and NS, along with various gate dielectric materials with fixed EOT, are investigated in the point of threshold voltage ( ${V}_{\text {TH}}$ ) and on-state current ( ${I}_{ {\mathrm {\scriptstyle{ON}}}}$ ). When high- ${k}$ gate dielectric is adopted, the large cross-sectional area of IB will provide a better ON-state characteristic because of the larger tunneling area. Compared with the conventional NS RFET, ${I}_{ {\mathrm {\scriptstyle{ON}}}}$ of tree-type RFET with IB width ( ${W}_{\text {IB}}$ ) = 5 nm, NS space ( ${S}_{\text {NS}}$ ) = 25 nm, and HfO₂ gate dielectric is separately demonstrated to improve by 44.6% and 60.2% for n- and p-type program, while in the case of SiO₂ gate dielectric, suitable size parameters should be selected to obtain an improved ON-state current because of the tunneling strength. The underlying physical mechanism is discussed in detail.