室温制备非晶ZnO薄膜及其电阻开关特性研究

发布时间：2018-03-12 20:21

本文选题：深紫外照射　切入点：室温　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：电阻式存储器(ReRAM)凭借其与CMOS工艺很好的兼容性、超快的擦写速度、极低的功耗、结构简单、可高密度集成等优点,近几年成为下一代非挥发性存储器的研究重点。最近柔性电子器件因其独特的柔性,延展性以及可折叠,低成本制造工艺等优点而受到广泛的关注,越来越多关于ReRAM的研究开始关注在低温下进行制备。因此本论文用室温下深紫外固化的方法取代溶胶凝胶方法中的高温退火制备了氧化锌薄膜,XRD分析结果表明薄膜为非晶的,XPS分析结果表明薄膜的主要成分是ZnO。在深紫外固化后的薄膜表面溅射Al作为顶电极获得Al/a-ZnO/FTO结构的器件,研究深紫外照射时间对器件电阻转变性能的影响,进一步解释了深紫外固化的机制。研究表明经过充足时间(12 h)照射的器件表现出双极性电阻开关特性,阈值电压分布集中(-3.7 VVset-2.9 V,3.4 VVreset4.3 V)且符合低电压工作的要求,至少在4000s内器件的高低阻态都没有没有发生明显的退化,表现出了良好的存储器特性。Al/a-ZnO/FTO器件的这种电阻转变特性可以用空间电荷限制电流传导机制解释。最后在上述研究的基础上用柔性的ITO/PET衬底取代FTO/玻璃衬底,并用不易氧化的Ag取代了易被氧化的Al作为顶电极在室温下采用同样的深紫外固化的方法制备得到了柔性的Ag/a-ZnO/ITO结构的柔性器件,并探究了Al和Ag这两种不同的金属材料作为上电极时整个阻变存储器件的电荷传输机制的不同,Ag/a-ZnO/ITO结构在高阻态的电荷传输符合Frenkel-Poole发射类型,在低阻态符合欧姆传导定律。最后对器件的机械柔韧性,电阻开关特性进行了研究。
[Abstract]:Resistive memory (RRAM) has the advantages of good compatibility with CMOS process, super fast writing speed, extremely low power consumption, simple structure, high density integration, etc. In recent years, flexible electronic devices have attracted wide attention due to their unique flexibility, ductility, foldable and low-cost manufacturing processes. More and more researches on ReRAM have focused on the preparation at low temperature. Therefore, in this thesis, ZnO thin films were prepared by deep ultraviolet curing at room temperature instead of high temperature annealing in sol-gel method. The results of X-ray photoelectron spectroscopy (XPS) show that the main component of the films is ZnO.The deposited Al on the surface of the films after deep UV curing is used as the top electrode to obtain the Al/a-ZnO/FTO structure. The effect of external irradiation time of deep violet on the resistance transition performance of the device is studied, and the mechanism of deep ultraviolet curing is explained. The results show that the device irradiated with deep violet for 12 h) exhibits the characteristics of bipolar resistance switch. The threshold voltage distribution is concentrated at -3.7 VVset-2.9 V ~ (3. 4) V) and meets the requirements of low voltage operation. At least in 4000 s, there is no obvious degradation of the high and low resistance state of the device. The resistance transition characteristics of Alra-ZnO / FTO devices can be explained by the space-charge-limited current conduction mechanism. Finally, the flexible ITO/PET substrates are used to replace the FTO/ glass substrates. The flexible devices with flexible Ag/a-ZnO/ITO structure were prepared by the same deep ultraviolet curing method at room temperature using the non-oxidized Ag instead of the easily oxidized Al as the top electrode at room temperature. The different charge transport mechanisms of the whole resistive memory device with Al and Ag as the upper electrode are investigated. The charge transfer in the high resistance states of Al / Ag / ZnO / ITO / ITO structure accords with the type of Frenkel-Poole emission. In the low resistance state, the ohmic conduction law is obeyed. Finally, the mechanical flexibility and resistance switch characteristics of the device are studied.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.2;TP333

【参考文献】