Performance Improvement of Spacer-Engineered N-Type Tree Shaped NSFET Toward Advanced Technology Nodes

Tree-shaped Nanosheet FETS (NSFET) is the most dependable way to scale down the gate lengths deep. This paper investigates the 12nm gate length (LG) n-type Tree-shaped NSFET with the gate having a stack of high-k dielectric (HfO2) and SiO2 using different spacer materials, which can be done using TCAD simulations. The Tree-shaped NFET device with {mathrm {T}}_{mathrm {(NS)}} =5 nm, {mathrm {W}}_{mathrm {(NS)}} =25 nm, {mathrm {W}}_{mathrm {IB}} =5 nm, and {mathrm {H}}_{mathrm {IB}} =25 nm has high on-current (I_{ON} ) and low off-current (I_{OFF} ). The 3D device with single-k and dual-k spacers are compared and its DC characteristics are shown. It is noted that the dual-k device achieves the maximum I_{ON}/I_{OFF} ratio, which is 10^{9} , compared to 10^{7} because the fringing fields with spacer dielectric lengthen the effective gate length. Additionally, the impact of work function, interbridge height, width, gate lengths, and temperature, along with the device's analog/RF and DC metrics, is also investigated in this paper. Even at 12 nm LG, the proposed device exhibits good electrical properties with DIBL =23 mV/V and SS =62 mV/dec and switching ratio (I_{ON}/I_{OFF}) = 10^{9}. The device's performance confirms that Moore's law holds even for lower technology nodes, allowing for further scalability.