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

Hf_0.5Zr_0.5O₂ (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.