AUTHOR=Wen Xin , Halter Mattia , Bégon-Lours Laura , Luisier Mathieu 

TITLE=Physical modeling of HZO-based ferroelectric field-effect transistors with a WOx channel

JOURNAL=Frontiers in Nanotechnology

VOLUME=Volume 4 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/nanotechnology/articles/10.3389/fnano.2022.900592

DOI=10.3389/fnano.2022.900592

ISSN=2673-3013

ABSTRACT=The DC and AC transfer characteristics of Hf$_{0.57}$Zr$_{0.43}$O$_2$ (HZO)-based ferroelectric field-effect transistors (FeFETs) with a WO$_x$ channel are investigated using a 2-D time-dependent Ginzburg-Landau model as implemented in a state-of-the-art technology computer aided design tool. Starting from an existing FeFET configuration, the influence of different design parameters and geometries is analyzed before providing guidelines for next-generation devices with an increased ``high ($R_H$) to low ($R_L$)" resistance ratio, i.e. $R_H/R_L$. The suitability of FeFETs as solid-state synapses in memristive crossbar arrays depends on this parameter. Simulations predict that a 13 times larger $R_H/R_L$ ratio can be achieved in a double-gate FeFET, as compared to a back-gated one with the same channel geometry and ferroelectric layer. The observed improvement can be attributed to the enhanced electrostatic control over the semiconducting channel thanks to the addition of a second gate. A similar effect is obtained by thinning either the HZO dielectric or the WO$_x$ channel. These findings could pave the way for FeFETs with enhanced synaptic-like properties that play a key role in future neuromorphic computing applications.