p-NiO/n-MgZnO异质结器件的电致阻变效应及相关机理研究

With enormous potential application in future resistive random accessory memory (RRAM), the multifunctional oxides exhibiting resistance switching are the current hot research area. For the practical application of RRAM, it is a crucial issue to improve the stability and anti-fatigue properties of the storage capabilities.Based on our previous investigation on resistive switching of MgZnO film deveces, the project plan to fabricate RRAM based on p-NiO/n-MgZnO p-n heterojunction, with an aim to improving the stability and anti-fatigue properties of devices by the presence of heterojunction interface. The project also tend to elucidate the fatigue mechanisms of resistance switching by the thorough investigation the inner correlation between the interfacial characteristics and resistance switching of p-n heterojunction devices. Furthermore, this project will help to clarify the physical mechanism of the resistance switching, to understand the effect of interfacial engineering and multi-functional coupling on performance of the devices, to optimize the structure and function of the MgZnO-based devices and provide the theoretical and experimental solution to better the performance of RRAM.

具有电致阻变特性的多功能氧化物材料在未来阻变式存储器上具有巨大应用潜力，是目前的热点研究领域，而提高电致阻变特性的稳定性和抗疲劳性能是其实际应用需要解决的技术关键。本项目在我们研究MgZnO薄膜器件电致阻变特性的基础上，创新性地提出采用p-NiO/n-MgZnO异质结构成器件。通过研究异质p-n结界面缺陷、载流子输运性质等界面特性与器件电致阻变特性之间的内在作用规律，阐释器件电致阻变特性的疲劳机理和微观物理机制,并利用异质结界面的作用，进一步提高器件的稳定性和抗疲劳特性。本课题的研究，将有助于澄清器件电致阻变特性的微观物理机制，加深界面效应及多功能耦合效应对器件性能影响规律的认识，为优化器件的结构和功能、获得高性能MgZnO薄膜阻变式存储器提供理论和实验依据。

基于过渡金属氧化物电致阻变特性的阻变式存储器在未来具有很大的应用空间，是目前的热点研究领域。本项目从存储器候选材料的选择及其制备工艺、器件结构、性能调控等方面开展研究。首先，采用非晶异质结构作为存储介质，通过控制器件限制电流的变换次序，实现了器件阻变特性的原位且非破坏性优化途径，提高了器件电致阻变特性的稳定性、抗疲劳性。然后，通过调控“Electroforming”过程的电压极性方向和限制电流，研究了器件从偶极性阻变效应至互补型阻变效应的过渡阶段，并获得了稳定的互补型阻变效应和一次性写入重复读取（WORM）的存储特性，可分别用于抑制集成器件的漏电路径和永久性的数据存储。本项目研究工作的完成，不仅完善了电致阻变特性的调控方式及其微观物理机制等理论，也为阻变式存储器的应用提供实验依据。