Physical Insights Into the Performances of Negative Capacitance Field Effect Transistors Using Single-Domain Versus Multidomain Models

In this study, the performances of negative capacitance field effect transistors (NCFETs) are compared by simulation using single-domain (SD) and multidomain (MD) models. Based on the MD model with the gradient energy coefficient, the ferroelectric (FE) polarization distribution is investigated. The results reveal the correlation among the FE polarization distribution, the NC effect, and the device performances for different device parameters, including the FE thickness (
${T}_{\mathrm{FE}}$
) and the oxide thickness (
${T}_{\mathrm{OX}}$
). The FE polarization distribution tends to transform from the SD state into the MD state with the increase of
${T}_{\mathrm{FE}}$
and the decrease of
${T}_{\mathrm{OX}}$
. The increased
${T}_{\mathrm{FE}}$
and decreased
${T}_{\mathrm{OX}}$
could result in a more significant distinction in the FE polarization distribution and a further larger difference in the NC effect between the MD state and the conventional SD state for NCFETs. The phenomenon above is confirmed by transient characteristics in NCFETs. More analysis and design space of NCFETs are provided by the study results.