The effect of annealing temperature on resistive switching behaviors of HfO_x film

The HfO_x films annealed at different temperatures were fabricated. The crystal structure and chemical composition of the films showed strong dependence on annealing temperature. The prepared samples all exhibited bipolar resistive switching (RS) behavior. The results showed that the RS behaviors of HfO_x sample in terms of ON/OFF ratio and endurance property can be improved by low temperature annealing process, while the ON/OFF ratio would be greatly reduced by high temperature annealing process due to the increase of leakage current. The 200 °C annealed sample showed good RS performance. The two resistance states can be easily distinguished in a range of 10³ over 100 switch cycles. The RS mechanisms of prepared HfO_x films were studied and interpreted based on space-charge-limited current effect.