Vertically Stacked Nanosheets Tree-Type Reconfigurable Transistor With Improved ON-Current
Yabin Sun, Xianglong Li, Ziyu Liu, Yun Liu, Xiaojin Li, Yanling Shi
Abstract
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 (<inline-formula> <tex-math notation="LaTeX">${V}_{\text {TH}}$ </tex-math></inline-formula>) and on-state current (<inline-formula> <tex-math notation="LaTeX">${I}_{ {\mathrm {\scriptstyle{ON}}}}$ </tex-math></inline-formula>). When high-<inline-formula> <tex-math notation="LaTeX">${k}$ </tex-math></inline-formula> 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, <inline-formula> <tex-math notation="LaTeX">${I}_{ {\mathrm {\scriptstyle{ON}}}}$ </tex-math></inline-formula> of tree-type RFET with IB width (<inline-formula> <tex-math notation="LaTeX">${W}_{\text {IB}}$ </tex-math></inline-formula>) = 5 nm, NS space (<inline-formula> <tex-math notation="LaTeX">${S}_{\text {NS}}$ </tex-math></inline-formula>) = 25 nm, and HfO<sub>2</sub> gate dielectric is separately demonstrated to improve by 44.6% and 60.2% for n- and p-type program, while in the case of SiO<sub>2</sub> 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.