103 dc sweep, the HRS and LRS maintain a stable resistance ratio higher than ten without decay, as shown in Fig. 6a. The dispersion of operation voltages demonstrates the high switching uniformity, as shown in Fig. 6b.Figure 6c shows their good data storage ability (3×104 s) under 100 mV stress at 85 oC with nondestructive read-out. Conclusion In conclusion, this study shows that inserting a Hf metal layer into a Pt/HfO2/TiN device and subjecting it to a PMA process creates a Pt/Hf/HfO2/TiN device that exhibits polarity reversion in the resistive switching property. Inserting a Hf metal layer and performing the PMA process activated the Hf metal layer as an oxygen storage layer, which makes redox fixed near the interface between the Hf metal and the HfO2 thin film. Consequently, the interface generation (HfOx) that makes the conduction mechanism switch to SCLC mechanism from Poole-Frenkel emission, leading to a polarity reversion. The proposed Pt/Hf/HfO2/TiN devices also exhibited good resistive switching characteristics and switching uniformity, with a operation, 103 dc sweep endurance, and 3×104 s retention test at 85 oC. Acknowledgments The authors would like to express heartfelt thanks to the Prof. S.-J. Lin and the late Prof. T.-B. Wu from National Tsing-Hua University. C.-S. Peng is grateful to Dr. D.-T. Lee and G.H. Group for their helpful discussions. We also appreciate the Industrial Technology Research Institute of Taiwan (under Contract A351AA5110)and National Science Council of Taiwan (under Contract NSC 101-2120-M-007-003) for providing financial support.
103 dc sweep, the HRS and LRS maintain a stable resistance ratio higher than ten without decay, as shown in Fig. 6a. The dispersion of operation voltages demonstrates the high switching uniformity, as shown in Fig. 6b.Figure 6c shows their good data storage ability (3×104 s) under 100 mV stress at 85 oC with nondestructive read-out. Conclusion In conclusion, this study shows that inserting a Hf metal layer into a Pt/HfO2/TiN device and subjecting it to a PMA process creates a Pt/Hf/HfO2/TiN device that exhibits polarity reversion in the resistive switching property. Inserting a Hf metal layer and performing the PMA process activated the Hf metal layer as an oxygen storage layer, which makes redox fixed near the interface between the Hf metal and the HfO2 thin film. Consequently, the interface generation (HfOx) that makes the conduction mechanism switch to SCLC mechanism from Poole-Frenkel emission, leading to a polarity reversion. The proposed Pt/Hf/HfO2/TiN devices also exhibited good resistive switching characteristics and switching uniformity, with a operation, 103 dc sweep endurance, and 3×104 s retention test at 85 oC. Acknowledgments The authors would like to express heartfelt thanks to the Prof. S.-J. Lin and the late Prof. T.-B. Wu from National Tsing-Hua University. C.-S. Peng is grateful to Dr. D.-T. Lee and G.H. Group for their helpful discussions. We also appreciate the Industrial Technology Research Institute of Taiwan (under Contract A351AA5110)and National Science Council of Taiwan (under Contract NSC 101-2120-M-007-003) for providing financial support.