High endurance and low coercive voltage ferroelectric tunnel junction by electrode engineering

In this paper, we report a high endurance and low coercive voltage (Vc) ferroelectric tunnel junction (FTJ) device by replacing the TiN top electrode with W electrode after annealing. This method implants a TiNOx thin layer, which reduces leakage current and increases breakdown voltage (Vbd), leading to better device endurance. It can also effectively promote the formation of orthogonal phase and inhibit tetragonal phase during the wake-up process, which contributes to reducing Vc. Therefore, the proposed 5 nm H0.5Z0.5O2 (HZO) FTJ exhibits excellent performances, such as low Vc (0.49 V), small Vc/Vbd ratio (19.1%), high endurance (>1011), and high double remanent polarization (2Pr = 41 μC/cm2), which are the frontier of the reported HfO2-based FTJ. The results strongly indicate that the FTJ has high potential in addressing the frequent weight changes generated by brain-like computational training and learning.