Study of resistive switching behavior in HfO₂nanocrystals synthesized via a low temperature hydrothermal method

The resistive switching property in HfO₂have attracted increasing interest in recent years. In this work, amorphous HfO₂nanocrystals are synthesized by a facile hydrothermal method. Then, the as-synthesized nanocrystals are rapid thermal annealed in different atmospheres for improving the crystal quality, and monoclinic phase is determined as the main crystal structure of the annealed HfO₂. Subsequently, metal-insulator-metal structure devices based on HfO₂samples are fabricated. Electrical measurement indicates that 700 °C annealing processes in Air and Ar environments can slightly improve the bipolar resistive switching and retention behaviors. Higher annealed temperature (900 °C) will further improve the crystal quality of HfO₂, while the resistive switching and retention behaviors of the devices continuously attenuate, which can be ascribed to the reduction of the conductive filaments induced by defects.