Reliability of TCAD study for HfO2-doped Negative capacitance FinFET with different Material-Specific dopants

Abstract

Attaining the ferroelectric (FE) polarization in a thin HfO2 layer using a specific dopant is a widely adopted way to realize Negative Capacitance (NC) FET. In a general TCAD simulation study of NC-based devices, the NC property of the FE layer is strongly dependent on the values of Landau parameters (α,β,γ,ρ,g), which are unique for specific dopants and FE thickness. In this paper, for the first time, we investigated the reliability of TCAD simulations with which NC FinFET is simulated for a specific dopants-based FE-HfO2 layer. The possible dopants used to realize a thin-HfO2 layer as a FE layer are Al, Gd, La, Si, Sr, Y, and Zr. Each dopant has different (α,β,γ,ρ,g) and thus offers a different NC regime of operation, i.e., S-curve. α and β are the dominant parameters if we consider the uniform polarization under quasi-static analysis. Further, the change in ambient temperature alters the value of α, resulting in changes in the NC-state. Hence, for the reliable TCAD-based NC study, the precise selection of Landau parameters and dopants is needed for optimized performances.