Hf0.5Zr0.5O₂-Based Ferroelectric Field-Effect Transistors With HfO₂ Seed Layers for Radiation-Hard Nonvolatile Memory Applications
Chen Liu, Wenwu Xiao, Yue Peng, Binjian Zeng, Shuaizhi Zheng, Lu Yin, Qiangxiang Peng, Xiangli Zhong, Min Liao, Yichun Zhou
Abstract
Hf <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Zr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (HZO)-based ferroelectric field-effect transistors (FeFETs) with HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> seed layer were investigated for radiation-hard nonvolatile memory applications. First, it was found that the HZO thin films grown on HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> seed layer showed improved crystallinity and ferroelectricity compared with those directly grown on SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> thin film, leading to a larger memory window (MW), better endurance, and retention properties of the HZO-based FeFETs with HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> seed layers. Moreover, after 1 Mrad(Si) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sup> Co γ-ray irradiation, the memory properties of the HZO-based FeFETs with HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> seed layer were also better than those without the HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> seed layer. Especially, the HZO-based FeFETs with an HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> seed layer have a larger remaining MW (0.66 V) than that (0.29 V) of the FeFETs without an HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> seed layer after 1×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> program/erase cycle. This work represents a first attempt to realize the high performances of radiation-hard HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based FeFETs.