Modeling the Coupled Charge Trapping Dynamics in FeFETs for Reliability Characterizations

In this article, a compact physics framework is established to characterize the reliability-related defects in ferroelectric field effect transistors (FeFETs). The two-state nonradiative multiphonon (NMP) theory is solved with coupling to a Monte Carlo nucleation-limited switching (MCNLS) ferroelectric (FE) module. Charge trapping and de-trapping are hence calculated in the consistency with the electrostatic potentials of FeFETs. The measured read-after-write data of n-type FeFETs is well reproduced, indicating shallow traps with low relaxation energy (S) and high trap energy level (
${E} _{\text {t}}\text {)}$
. At the same time, experimentally observed FeFET memory windows (MWs) featuring different trends of low-
${V} _{\text {th}}$
(LVT)/high-
${V} _{\text {th}}$
(HVT) states shifting are explained with deep traps of different configurations, i.e., with higher S and lower
${E} _{\text {t}}$
. This framework not only facilitates reasonable explanations of FeFET reliability mechanisms for further optimizations but also provides a defect-aware approach for FeFET-based neuromorphic and compute-in-memory (CiM) applications.