Promote Hf0.5Zr0.5O2 FTJs ON/OFF by Thermal Rewake-Up Operation for Neuromorphic Computing

The Hf0.5Zr0.5O2-based ferroelectric tunnel junction (FTJ) devices are fabricated and further enhanced by a proposed “thermal rewake-up” (TR) operation at different high temperatures. The measured electrical characteristics show that TR operation can significantly enhance the ferroelectric remnant polarization (Pr) up to
$29.1~\mu \text{C}$
/cm2, and can boost the FTJ resistance ON/OFF ratio from 9.8 to 34.9, meantime achieving
$10^{{5}}$
cycles endurance and
$10^{{4}}$
s data retention. Furthermore, the neural network adopting TR FTJ devices as electronic synapses exhibits improved accuracy from 95.76% to 98.81% and enhanced tolerance to noise in the task of handwritten digit recognition. Hence, this letter demonstrates a feasible approach to improve the switching behavior of FTJ devices in applications of binary/multi-level memories and neuromorphic computing.