Pure ZrO 2 Ferroelectric Thin Film for Nonvolatile Memory and Neural Network Computing.

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.