Department of Physics, National Sun Yay-Sen University, Kaohsiung 804, Taiwan.
Nanoscale. 2017 Jun 29;9(25):8586-8590. doi: 10.1039/c7nr02305g.
This study proposes a method for a HfO-based device to exhibit both resistive switching (RS) characteristics as resistive random access memory (RRAM) and selector characteristics by introducing vanadium (V) as the top electrode. This simple V/HfO/TiN structure can demonstrate these two different properties depending on forming polarities. The RS mechanism is activated by a positive forming bias. In contrast, the selector property is induced by a negative forming bias. The material analyses firstly confirm the existence of V in the top electrode. Then the electrical measurements for the same V/HfO/TiN structures but with different forming polarities were carried out to further investigate their DC sweeping characteristics to act as either a selector or RRAM device. Furthermore, reliability tests for both selector and RRAM devices were also conducted to confirm their switching stabilities. Finally, current fitting methods and temperature influence experiments were performed to investigate the carrier transport mechanisms. Finally, physical models were proposed to illustrate the selector property and RS mechanism for selector and RRAM devices, respectively. This simple device structure with its easy operating method accomplishes a significant advancement of devices combining both selector properties and RRAM for remarkable real applications in the near future.
本研究提出了一种基于 HfO 的器件方法，通过引入钒（V）作为顶电极，使其同时表现出电阻开关（RS）特性和选择器特性。这种简单的 V/HfO/TiN 结构可以根据形成极性展示这两种不同的性质。RS 机制通过正形成偏压激活。相比之下，选择器特性是由负形成偏压引起的。材料分析首先证实了顶电极中 V 的存在。然后对具有不同形成极性的相同 V/HfO/TiN 结构进行了电测量，以进一步研究它们作为选择器或 RRAM 器件的直流扫描特性。此外，还对选择器和 RRAM 器件进行了可靠性测试，以确认其开关稳定性。最后，进行了电流拟合方法和温度影响实验，以研究载流子输运机制。最后，提出了物理模型来分别说明选择器和 RRAM 器件的选择器特性和 RS 机制。这种具有简单结构和易于操作的方法的器件，为在不久的将来在实际应用中显著结合选择器特性和 RRAM 的器件提供了重要的进展。
