基于低温原子层淀积技术的柔性阻变存储器的研究

发布时间：2018-02-28 20:45

本文关键词： 金属氧化物性能优化机理分析柔性电子电阻式存储器低温原子层淀积　出处：《复旦大学》2013年硕士论文　论文类型：学位论文

【摘要】：随着半导体工艺技术的不断发展,人们能够获得的电子产品越来越先进,越来越高端。与此同时,由于诺基亚和苹果对柔性概念机的推出,人们纷纷将目光投向未来的柔性电子产品,目前,柔性电子产品的研究还只是处于探索阶段,虽然已经有一些半导体厂商开始尝试生产和销售柔性LED等柔性显示产品,但是产品的性能跟目前基于CMOS系统的硅基产品相比还是有很大差距的。为了实现这一目标,最基础的工作便是在柔性衬底上,制备出性能优越的存储器件,究其性能要求要低于其他的功能器件,如逻辑器件、射频器件、传感器件等。此外,由于信息社会的不断膨胀,人们对数据的需求不断增长,因此对存储密度、速度、成本和功耗的要求与日俱增。目前主流的flash存储器已经由于自身的结构限制,正面临着严峻的挑战,一些新型的非挥发存储器开始进入人们的目光,然而这些存储器也有自己的一些缺点,目前还不能成为flash的替代者。近年来,RRAM开始不断受到工业界和学术界的亲睐以其结构简单、微缩能力强、保持时间长、操作电压低一级与传统CMOS工艺兼容等特点。本论文首先从对RRAM器件相比其他新兴存储器件的优点出发,同时介绍了当今比较具有优势的薄膜淀积技术—原子层淀积技术(ALD),同时比较了其他的一些薄膜淀积技术的优劣性。通过利用低温原子层淀积技术(LTALD)在柔性衬底上生长和制备二元金属氧化物薄膜出发,对这些制成的薄膜进行了材料表征,结果显示通过LTALD技术制备的薄膜和传统ALD技术淀积的薄膜拥有相同的质量。这一结果,使得在柔性衬底上低温方法淀积薄膜成为可能,并且能够成为未来薄膜器件的主要制备手段之一。其次,从基于LTALD制备的二元金属氧化物的FRRAM器件着手,介绍了器件的制备方法,并研究和分析了基于TiN/Al2O3/ITO和TiN/HfO2/ITO结构的器件的阻变特性、耐擦写特性以及数据保持特性,并整理和总结了基于high-k薄膜和MIM结构的FRRAM器件的电流机制。最后,通过使用堆栈结构,对FRRAM器件的性能进行了优化,并对堆栈结构的厚度也进行了优化,通过优化的器件显示出了相当优异的阻变和数据保持性能,以及在擦写过程中操作电压的一致性和集中分布性。同时,在通过对堆栈结构FRRAM电流机制和阻抗分析,得出了FRRAM器件的微观阻变机理和等效电路,为后来FRRAM器件的深入研究提供了思路。在本论文末尾,对本文的实验工作进行了总结论述,并对FRRAM的未来和柔性电子的未来发展做出了展望。
[Abstract]:With the continuous development of semiconductor technology, more and more advanced and high-end electronic products are available. At the same time, thanks to the introduction of flexible concept machines by Nokia and Apple, People are looking to the future flexible electronic products. At present, the research of flexible electronic products is only in the exploratory stage, although some semiconductor manufacturers have begun to try to produce and sell flexible display products such as flexible LED. However, the performance of the product is still far from that of the silicon-based products based on CMOS system. In order to achieve this goal, the most basic work is to fabricate superior performance memory devices on flexible substrates. Its performance requirements are lower than other functional devices, such as logic devices, RF devices, sensor devices and so on. In addition, due to the continuous expansion of the information society and the increasing demand for data, the demand for storage density, speed, cost and power consumption is increasing. At present, the mainstream flash memory has been limited by its own structure. Faced with severe challenges, some new non-volatile memory began to enter the eyes of people, but these memories also have their own shortcomings, In recent years, it has been attracting more and more attention from industry and academia for its simple structure, strong microscopicity, long retention time, low operating voltage and compatibility with traditional CMOS process. In this paper, firstly, the advantages of RRAM devices compared with other emerging memory devices are discussed. At the same time, this paper introduces the advantage of the current thin film deposition technology, atomic layer deposition technology, and compares the advantages and disadvantages of some other thin film deposition technologies. By using the low temperature atomic layer deposition technology, we use LTALDon the flexible substrate, and compare the advantages and disadvantages of some other thin film deposition technologies on the flexible substrate by using the low temperature atomic layer deposition technology (LTALDD). Growth and preparation of binary metal oxide films, The results show that the films prepared by LTALD technology have the same quality as those deposited by traditional ALD technology. This result makes it possible to deposit thin films on flexible substrates at low temperature. And it can become one of the main fabrication methods of thin film devices in the future. Secondly, the fabrication methods of FRRAM devices based on binary metal oxides based on LTALD are introduced. The resistive characteristics, write-resistant characteristics and data retention characteristics of FRRAM devices based on TiN/Al2O3/ITO and TiN/HfO2/ITO structures are studied and analyzed. The current mechanism of FRRAM devices based on high-k thin films and MIM structures is summarized. Finally, by using stack structure, the current mechanism of FRRAM devices based on high-k thin film and MIM structure is summarized. The performance of FRRAM device is optimized, and the thickness of stack structure is optimized. The optimized device shows excellent resistance and data retention performance. At the same time, by analyzing the current mechanism and impedance of stack structure FRRAM, the micro resistance mechanism and equivalent circuit of FRRAM device are obtained. At the end of this paper, the experimental work of this paper is summarized and discussed, and the future of FRRAM and flexible electronics are prospected.
【学位授予单位】：复旦大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TP333

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