Pure ZrO2 Ferroelectric Thin Film for Nonvolatile Memory and Neural Network Computing

The recent discovery of ferroelectricity in pure ZrO₂ has drawn much attention, but the information storage and processing performances of ferroelectric ZrO₂-based nonvolatile devices remain open for further exploration. Here, a ZrO₂ (∼8 nm)-based ferroelectric capacitor using RuO₂ oxide electrodes is fabricated, and the ferroelectric orthorhombic phase evolution under electric field cycling is studied. A ferroelectric remnant polarization (2P_r) of >30 μC/cm², leakage current density of ∼2.79 × 10^-8 A/cm² 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 ZrO₂ devices for nonvolatile memory and artificial neural network computing.