Reliability characteristics and conduction mechanisms in resistive switching memory devices using ZnO thin films

摘要

In this work, bipolar resistive switching characteristics were demonstrated in the Pt/ZnO/Pt structure. Reliability tests show that ac cycling endurance level above 10⁶ can be achieved. However, significant window closure takes place after about 10² dc cycles. Data retention characteristic exhibits no observed degradation after 168 h. Read durability shows stable resistance states after 10⁶ read times. The current transportation in ZnO films is dominated by the hopping conduction and the ohmic conduction in high-resistance and low-resistance states, respectively. Therefore, the electrical parameters of trap energy level, trap spacing, Fermi level, electron mobility, and effective density of states in conduction band in ZnO were identified.