Pure ZrO<sub>2</sub> Ferroelectric Thin Film for Nonvolatile Memory and Neural Network Computing
Zijian Wang, Zeyu Guan, He Wang, Xiang Zhou, Jiachen Li, Shengchun Shen, Yuewei Yin, Xiaoguang Li
Abstract
The recent discovery of ferroelectricity in pure ZrO 2 has drawn much attention, but the information storage and processing performances of ferroelectric ZrO 2 -based nonvolatile devices remain open for further exploration. Here, a ZrO 2 (∼8 nm)-based ferroelectric capacitor using RuO 2 oxide electrodes is fabricated, and the ferroelectric orthorhombic phase evolution under electric field cycling is studied. A ferroelectric remnant polarization (2 P r ) of >30 μC/cm 2, leakage current density of ∼2.79 × 10 –8 A/cm 2 at 1 MV/cm, and estimated polarization retention of >10 years are achieved. When the ferroelectric capacitor is connected with a transistor, a memory window of ∼0.8 V and eight distinct states can be obtained in such a ferroelectric field-effect transistor (FeFET). Through the conductance manipulation of the FeFET, a high object image recognition accuracy of ∼93.32% is achieved on the basis of the CIFAR-10 dataset in the convolutional neural network (CNN) simulation, which is close to the result of ∼94.20% obtained by floating-point-based CNN software. These results demonstrate the potential of ferroelectric ZrO 2 devices for nonvolatile memory and artificial neural network computing.