Challenges to Partial Switching of Hf0.8Zr0.2O2 Gated Ferroelectric FET for Multilevel/Analog or Low-voltage Memory Operation

Abstract

The ability to partially switch an FeFET could enable their use as an embedded low-voltage memory and as analog weight storage in artificial neural networks (ANNs). We report on memory characterization of FeFETs gated with 5.5-nm Hf0.8Zr0.2O2, fabricated on fully depleted silicon-on-insulator using a self-aligned, gate last process. We find that for a single device, excellent elevated temperature retention, program/erase endurance, and read endurance are obtained; however, there is significant device to device variability in the response of the ferroelectric to a partially switching program pulse, which may require the use of feedback in programming.