基于氧化石墨烯的阻变存储器机理及其性能研究

发布时间：2018-04-17 01:17

本文选题：阻变式随机存储器 + 氧化石墨烯　；参考：《东北师范大学》2017年硕士论文

【摘要】：按照摩尔定律的发展规律,传统的浮栅存储器受限于电荷遂穿等原因,尺寸已经逼近物理极限,难以满足大数据存储的需求。开发基于不同工作机理和结构的新型信息存储器件有助于突破这种摩尔定律限制。非易失性阻变存储器(RRAM)由于其转换速度快、保持时间长、功耗低以及器件结构简单等优点引起人们的关注。传统的RRAM器件是金属/绝缘体/金属(M/I/M)这种三明治结构,通过电学信号刺激实现器件阻态变化来进行信息存储。目前为止在很多种材料中发现电阻转变效应,包括金属氧化物、金属硫化物、有机物、非晶硅、碳等。氧化石墨烯(GO)材料以其独特的光电特性,在微电子领域展示出良好的应用前景。GO材料具有制备工艺简单,可大面积成膜、电学性质易于调控等优点近年来被用于阻变存储器件研究。研究表明GO在展示出电致阻变特性的同时兼具柔性、透明等优点,是极具潜力的下一代存储材料。然而,GO基RRAM的阻变机理尚不明确,器件性能较低等问题一直制约其进一步发展。因此,本论文在氧化石墨烯阻变存储器工作机理、器件阻变性能提升等方面展开工作。具体研究如下:阻变工作机理探究:利用具有不同氧活性的电极构筑了Al/GO/Al器件、Au/GO/Au器件,探究了不同电极的氧化石墨烯基阻变存储器的阻变行为。通过器件电学特性表征、电子传导机制研究,初步证实了其阻变机制是sp2和sp3态的相互转换的过程。利用紫外光刻的方法构筑平面结构的Au/GO/Au微尺度器件,通过对原位观测GO阻变过程中材料结构变化以及利用XPS能谱、Raman光谱表征GO材料阻变前后的成分变化进行分析,进一步明确了GO阻变机理。阻变性能提升探究:针对GO阻变存储器件导电通道形成与断开过程的随机性导致的器件参数波动性以及转变电压较大等问题,本论文采用TiO2纳米粒子掺杂以及紫外光辐照等方法,在GO内部构筑局域化电场来控制材料内部氧分布。研究表明,局域电场能够降低导电通道的随机性,有效提升器件阻变稳定性,此外,器件功耗也被有效地降低。该方法是一种简单、实用的优化GO阻变存储器稳定性的手段。
[Abstract]:According to the law of Moore's law, the traditional floating gate memory is limited by charge tunneling, and the size is close to the physical limit, so it is difficult to meet the storage requirements of big data.The development of new information storage devices based on different working mechanisms and structures is helpful to break through the limitation of Moore's law.Non-volatile resistive memory (RRAM) has attracted much attention due to its high conversion speed, long retention time, low power consumption and simple device structure.The traditional RRAM device is a sandwich structure of metal / insulator / metal / metal / I / I / M, which stores the information by electrical signal stimulation.So far, resistance transition effects have been found in many materials, including metal oxides, metal sulfides, organic compounds, amorphous silicon, carbon and so on.Because of its unique optoelectronic properties, graphene oxide (GOO) materials have shown good application prospects in the field of microelectronics. Go materials have a simple preparation process and can be used to form films in a large area.Electrical properties are easy to control and have been used in the study of resistive memory devices in recent years.It is shown that go has the advantages of flexibility and transparency, and it is the next generation storage material with great potential.However, the resistance mechanism of go based RRAM is not clear, and the low performance of the device has been restricting its further development.Therefore, the mechanism of graphene oxide resistive memory and the improvement of device resistance performance are studied in this paper.The specific research is as follows: the mechanism of resistance work: Al/GO/Al devices are fabricated by using the electrodes with different oxygen activity. The resistance behavior of graphene oxide based resistive memory with different electrodes is investigated.The electrical properties of the device and the study of the electron conduction mechanism indicate that the resistance mechanism is a process of interconversion between sp2 and sp3 states.Au/GO/Au microdevices with planar structure were constructed by UV lithography. The changes of material structure during go resistance were observed in situ and the composition changes before and after go resistance were characterized by XPS spectroscopy.The mechanism of go resistance is further clarified.Research on the improvement of Resistance performance: aiming at the problem of the fluctuation of device parameters and the large transition voltage caused by the randomness of the formation and disconnection of conductive channels in go resistive memory devices,In this paper, TiO2 nanoparticles were doped and ultraviolet radiation was used to construct localized electric field inside go to control the oxygen distribution in the material.It is shown that the local electric field can reduce the randomness of the conductive channel, effectively enhance the device resistance stability, in addition, the device power consumption is also effectively reduced.This method is a simple and practical method to optimize the stability of go resistive memory.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.11;TP333

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