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

Hf
_0.5
Zr
_0.5
O
₂
(HZO)-based ferroelectric field-effect transistors (FeFETs) with HfO
₂
seed layer were investigated for radiation-hard nonvolatile memory applications. First, it was found that the HZO thin films grown on HfO
₂
seed layer showed improved crystallinity and ferroelectricity compared with those directly grown on SiO
₂
thin film, leading to a larger memory window (MW), better endurance, and retention properties of the HZO-based FeFETs with HfO
₂
seed layers. Moreover, after 1 Mrad(Si)
⁶⁰
Co γ-ray irradiation, the memory properties of the HZO-based FeFETs with HfO
₂
seed layer were also better than those without the HfO
₂
seed layer. Especially, the HZO-based FeFETs with an HfO
₂
seed layer have a larger remaining MW (0.66 V) than that (0.29 V) of the FeFETs without an HfO
₂
seed layer after 1×10
⁴
program/erase cycle. This work represents a first attempt to realize the high performances of radiation-hard HfO
₂
-based FeFETs.