Wang Jianfeng, Song Zhongxiao, Xu Kewei, Liu Ming
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
J Nanosci Nanotechnol. 2010 Nov;10(11):7088-91. doi: 10.1166/jnn.2010.2758.
40 nm thick amorphous ZnO thin films were deposited by radio frequency magnetron sputtering at room temperature and asymmetric electrical switching characteristics are observed in the macroscopic symmetric Pt/ZnO/Pt structure. The crystal structure was examined by X-ray diffraction (XRD). The chemical bonding states of ZnO resistive switching layer was investigated by X-ray photoelectron spectroscopy (XPS). Keithley 4200 semiconductor characterization system was used to measure the current-voltage (I-V) characteristics of the fabricated devices. The results reveal that a reversible resistive switching behavior between the high resistance state and the low resistance state with rectifying effects can be repeated for more than 100 dc cycles. This asymmetric electrical behavior is thought to be related to the naturally self-formed PtOx between ZnO film and the Pt bottom electrode, which introduces an energy barrier when electrons flow from top electrode towards the bottom electrode. The model of Pt/ZnO/Pt memory cell is expected to be able to alleviate the misreading error in cross-point array for high density integrations.
通过射频磁控溅射在室温下沉积了40纳米厚的非晶氧化锌薄膜，并在宏观对称的Pt/ZnO/Pt结构中观察到了不对称的电开关特性。通过X射线衍射（XRD）对晶体结构进行了检测。利用X射线光电子能谱（XPS）研究了氧化锌电阻开关层的化学键合状态。使用吉时利4200半导体特性系统测量了所制备器件的电流-电压（I-V）特性。结果表明，在高电阻状态和低电阻状态之间具有整流效应的可逆电阻开关行为可以重复进行超过100次直流循环。这种不对称的电行为被认为与氧化锌薄膜和铂底部电极之间自然形成的PtOx有关，当电子从顶部电极流向底部电极时，它会引入一个能量势垒。预计Pt/ZnO/Pt存储单元模型能够减轻高密度集成交叉点阵列中的误读误差。
