Interdomain screening effect on polarization switching dynamics of BEOL-compatible ferroelectric field-effect transistors

Abstract

This study develops a physics-based modeling framework for back-end-of-line (BEOL)-compatible oxide-semiconductor-channel field-effect transistors (FeFETs), integrating nucleation-limited switching theory and technology computer-aided design technology. Based on this framework, the interdomain screening effect, which significantly modulates domain electric fields and subsequently impacts polarization switching dynamics, is systematically investigated as a focus herein. The core of this model lies in the asymmetric characterization of ferroelectric domains (denoted as PFE+/PFE−), which originates from the weak erase effect. This framework successfully reproduces the ID−VG hysteresis loops, achieving excellent consistency with experimental data including the abrupt current jump and asymmetric subthreshold swings, thereby validating the model's physical accuracy. Key findings reveal that the depolarization field not only acts as the intrinsic driver of polarization instability in individual ferroelectric domains but also modulates the switching behaviors of neighboring domains via the interdomain screening effect, ultimately constraining device reliability. This highlights the interdomain screening effect as a pivotal link between microscopic domain polarization and macroscopic device performance. Furthermore, the study uncovers the polarization reversal mechanism that underlies the memory window enhancement induced by channel length scaling. These results provide critical physical insights and actionable design guidance for optimizing the performance and reliability of BEOL-compatible FeFET devices.