Examination of the Interplay Between Polarization Switching and Charge Trapping in Ferroelectric FET

In this work, we evaluate the role of polarization switching and charge trapping in the operation of ferroelectric FET (FeFET) through combined experimental characterization and comprehensive modeling. We are demonstrating that: 1) the significant charge gap in the quasi-static split-CV (QSCV) and small signal CV is fundamental and not indicative of trapped charge density. This is because the QSCV senses the irreversible polarization switching while the small signal CV mainly probes the reversible domain wall displacement under ac excitation, theoretically yielding different scales of charge response in the two measurements. 2) Trapped charge density during memory write can be inferred from the measured charge release dynamics with the help of a comprehensive FeFET model that incorporates both the polarization switching and the charge trapping and release dynamics.