Memory effect of RF sputtered ZrO2 thin films

Abstract

Electrical properties of RF sputtered ZrO2 Memory thin films were investigated in this study. The device with structure AI/ZrO2/Pt shows a reproducible resistive switching behavior traced over 100 times at room temperature. Moreover, by using various top electrodes, such as Pt, Cu, Ni, Ag, Ti, and even W-probe, the resistive switching phenomenon can be observed in ZrO2-based memory with Pt bottom electrode, indicating that the ZrO2 bulk dominates the resistive switching. The bias polarity dependent resistive switching behavior is demonstrated in the Ti/ZrO2/Pt device, which might be due to interface reaction between Ti and ZrO2 film. The resistance value of high conductive state in the Ti/ZrO2/Pt device decreases with increasing current compliance implying the possibility for multi-bit storage. Besides, the Ti/ZrO2/Pt device can be operated over 2000 resistive switching cycles at 85 degrees C by sweeping DC voltage, and the two memory states demonstrate good stability under read voltage stress at room temperature and 95 degrees C. The write-read-erase-read operations can be over 10(3) cycles at 85 degrees C. No data loss is found upon successive readout before and after performing 10(3) endurance cycles at 85 degrees C. According to above experimental results, the ZrO2 thin film has high potential for nonvolatile memory application. (C) 2007 Elsevier B.V. All rights reserved.