Hf0.5Zr0.5O₂-Based Ferroelectric Field-Effect Transistors With HfO₂ Seed Layers for Radiation-Hard Nonvolatile Memory Applications

Hf0.5Zr0.5O2 (HZO)-based ferroelectric field-effect transistors (FeFETs) with HfO2 seed layer were investigated for radiation-hard nonvolatile memory applications. First, it was found that the HZO thin films grown on HfO2 seed layer showed improved crystallinity and ferroelectricity compared with those directly grown on SiO2 thin film, leading to a larger memory window (MW), better endurance, and retention properties of the HZO-based FeFETs with HfO2 seed layers. Moreover, after 1 Mrad(Si) 60Co $\gamma $ -ray irradiation, the memory properties of the HZO-based FeFETs with HfO2 seed layer were also better than those without the HfO2 seed layer. Especially, the HZO-based FeFETs with an HfO2 seed layer have a larger remaining MW (0.66 V) than that (0.29 V) of the FeFETs without an HfO2 seed layer after $1\times 10^{4}$ program/erase cycle. This work represents a first attempt to realize the high performances of radiation-hard HfO2-based FeFETs.