A surface potential model for tri-gate metal oxide semiconductor field effect transistor: Analysis below 10 nm channel length

Abstract

In this study, an analytical model of Tri-gate metal-oxide-semiconductor field effect transistor (TGMOSFET) for short channel lengths below 10 nm is suggested and Technology computer-aided design (TCAD) simulation is used for confirmation. Two dimensional (2D) Poisson’s equation is solved with symmetric and asymmetric double gate (DG) MOSFET separately and is combined using the perimeter-weighted sum approach to model the surface potential of lightly doped silicon TGMOSFET. The model is examined by varying channel length, oxide thickness, gate voltage, drain voltage and doping concentration. In this study, the ratio of channel length to width is always kept greater than or equal to two. The structure is also inspected with a high-k dielectric material. A relative study of hafnium oxide (HfO2) and silicon dioxide (SiO2) with identical oxide thicknesses is given to explore the effect of high dielectric material on the model of TGMOSFET. To obtain identical surface potentials, the oxide thickness of HfO2 must be larger than SiO2. Unlike SiO2, the minima of surface potential remain constant with channel length for HfO2. The outcome of the TCAD simulation is highly associated with the results of the analytical model. Therefore, to meet high packing density and low power consumption, TGMOSFET can be a potential candidate for ultra large scale integrated circuit (ULSI) technology.