基于微纳操控的石墨烯纳米器件制造基础理论与关键技术研究

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题名	基于微纳操控的石墨烯纳米器件制造基础理论与关键技术研究
作者	张嵛
学位类别	博士
答辩日期	2014-12-04
授予单位	中国科学院沈阳自动化研究所
授予地点	中国科学院沈阳自动化研究所
导师	席宁 ; 董再励
关键词	纳米操作机器人原子力显微镜石墨烯密度泛函理论光诱导介电泳纳米器件
其他题名	Study on the Basic Theory and Key Technologies of Graphene Nanodeviecs Fabrication Based on Micro-nano Manipulation
学位专业	模式识别与智能系统
中文摘要	随着微电子器件微型化的进程，‘硅工艺’正面临着严峻的挑战。而新兴的纳米制造技术将突破传统半导体制造工艺的极限，克服短通道效应、寄生电容、互联延迟以及功耗过大等问题，使微电子器件向着更小、更快、更冷发展。在众多的纳米材料中，石墨烯在室温下就具有超高的电子迁移率和载流子浓度，并且电阻率低，能耗极少，因此利用石墨烯可以制造出更小、更冷、更快的电子器件解决目前硅基微电子器件制造面临的技术瓶颈。然而尽管石墨烯在纳米器件方面已表现出不凡的性能，但是由于本征石墨烯没有能隙, 因此如何可控地在石墨烯中引入能隙是石墨烯走入实际应用的关键前提和当前研究热点。虽然研究者们已经发展了一些石墨烯加工技术并能够实现石墨烯的切割剪裁，但是现存的石墨烯加工技术都为“盲加工”，即在无法获得石墨烯晶格方向的前提下进行石墨烯的切割剪裁，从而无法可控地实现特定边缘结构石墨烯基纳米器件的加工制造，并且加工条件和加工过程通常较为复杂。针对上述挑战，本文利用纳米操作机器人技术开展了对石墨烯可控加工制造的创新性研究，研究内容主要包括：(1) 石墨烯构效关系与缺陷改性理论研究由于石墨烯器件的电学特性与其几何构型和边界结构密切相关，因此研究石墨烯几何构型与电特性间的构效关系，是制造石墨烯基功能器件的前提。本文基于密度泛函理论，首先对具有不同边缘结构的石墨烯纳米带（锯齿型和扶手椅型）的能带结构进行了研究，给出了石墨烯电特性与几何构型的构效关系；并针对石墨烯加工过程中可能引入缺陷问题，系统研究了不同缺陷结构和缺陷处于不同位置处对金属性质的锯齿型石墨烯带电学性质的影响。(2) 基于频率的石墨烯晶向检测技术研究石墨烯的晶向检测是实现特定边缘结构石墨烯基纳米器件的剪裁的关键问题。然而现存的原子分辨率成像技术，都只能用于离线结构观测，后续的切割加工过程将面临着加工位置再定位和对准的难题。针对这一难题，本文提出了基于摩擦力频域特征的石墨烯晶向检测方法。该方法仅利用一条或两条摩擦力扫描线即可在石墨烯加工前快速、准确地将石墨烯的晶向检测出来，并且该方法为在线监测，有效克服了加工位置对准难题。(3) 基于纳米操作机器人的石墨烯加工方法研究目前的石墨烯加工技术都为开环加工方式，由于剪裁过程中无信息反馈从而难以保证加工方向与期望晶向保持一致。原子力显微镜(Atomic Force Microscope，AFM)的探针除了作为终端执行器完成石墨烯的切割外，同时还能够作为力的检测装置实现纳米切割力的实时感知。因此，利用AFM系统研究了石墨烯晶向与切割力的关系，为构建基于实时力反馈的石墨烯可控加工方法奠定基础。(4) 石墨烯的可控装配技术与器件加工研究纳米装配技术是纳米器件制造的关键性前提，需要将构造的纳米结构排布或跨接在电极之间，实现对纳米材料的精确操控。针对传统介电泳技术难于实现石墨烯的可控和精确操控问题，通过结合微流控技术，探索研究了基于光诱导介电泳的石墨烯装配方法，实现了石墨烯的可控批量化装配；并在此基础上利用AFM机械加工方法制造了石墨烯FET(Field Effect Transistor)，并对其场效应特性进行了测试。本论文研究的意义在于研究探索一种石墨烯的可控纳米制造方法，包括晶向快速检测技术、基于纳米操作机器人的可控加工方法以及可控的规模化装配技术，为石墨烯纳米器件与纳米结构的加工制造发展提供了具有实际意义的理论方法和研究途径。
索取号	O613.71/Z36/2014
英文摘要	With the development of semiconductor industry, 'silicon technology' is facing severe challenges. However, the emerging nano-manufacturing technology will break through the limits of the traditional semiconductor manufacturing technology. By overcoming the problems such as short channel effects, parasitic capacitances, interconnection delay and large power consumption, nano-manufacturing technology will make microelectronic devices smaller, faster, and colder. Among nanomaterials, graphene has super-high carrier concentration and electron mobility at room temperature. In addition, electrons travel on graphene without any resistance, leading to very few energy consumption. Therefore, graphene can be used to make smaller, faster and colder electronic devices to break through the technical bottlenecks of current silicon based microelectronic manufacturing. Although graphene has shown excellent performance in nanodevices, the absence of energy band gap in graphene still stands as a grand challenge for its application in conventional semiconductor device. Therefore, how to controllably introduce bandgap in graphene are the key premise and research hotspots for practical applications. Although several methods have been developed and can realize the graphene patterning, these methods are “blind” manufacturing: graphene is fabricated without knowing the lattice orientations before manufacturing. Thus it is unable to cutting graphene into desired edge structures. In addition, the processing conditions are very strict and the process is very complex. In view of the above challenges, this paper carried out the innovation research on controllable graphene manufacturing and the research content mainly includes: (1) Theoretical research on electrical properties modification by geometries and defects Due to the electrical properties of graphene are strongly related to its size, geometry, and edge structure, the study on the relationship of graphene geometries and electrical properties is a prerequisite for graphene manufacturing. In this paper, the bandstructure of graphene nanoribbons with different edge structures has been studied based on the density functional theory. In addition, in the light of defects introduced in graphene fabrication process, the effect of defect patterns and locations in graphene on the electrical properties is systemically investigated. (2) The lattice orientation identification of graphene based on frequencies Graphene lattice orientation detection is a key problem to realize the nanodevice fabrication with specific edge structure. However, the existing atomic resolution imaging technology can only be used for off-line observation and the cutting process will be faced with the problem of relocation and calibration. With this challenge, a wavelet transform based frequency identification method was proposed for determination of graphene lattice orientations. This method only need one or two friction scanning signal for lattice orientation identification and it’s an on-line method which effectively overcomes the relocation and calibration problem. (3)Research on graphene manufacturing based on nano-robot Current graphene manufacturing methods are open-loop fabrication. It’s hard to guide the cutting direction along the desired lattice orientation in fabrication process without feedback. The probe of atomic force microscope (AFM) is not only a terminal executor for cutting, also can be a real-time sensor for cutting forces detection. Therefore, the systemic research on the relationship of cutting forces and lattice orientations has been carried out, which lay the foundation to build a close-loop fabrication strategy with real-time force as a feedback sensor to control the cutting direction. (4) Investigation on graphene controllable assembly and devices fabrication Nano-assembly technology is the key premise of nanodevices manufacturing. It needs to make the nanostructure connect with the microelectodes and to achieve precise manipulation of nanometer materials.Because the traditional dielectrophoresis technique is difficult to realize the controllable and precise manipulation, an assembly method combination with microfluidics and optically induced dielectrophoresis was studied to realize graphene controllable batch assembly; and on this basis, graphene-FET was fabricated using AFM mechanical cutting method and the field effect characteristics were tested. The significance of this thesis is to explore a controllable graphene manufacturing method, which includes fast lattice orientation identification, controllable fabrication based on nano-robot and large-scale assembly method. This research will provide meaningful theoretical and practical experiences for the research of graphene nanodevices fabrication.
语种	中文
产权排序	1
页码	100页
内容类型	学位论文
源URL	[http://ir.sia.ac.cn/handle/173321/16797]
专题	沈阳自动化研究所_机器人学研究室
推荐引用方式 GB/T 7714	张嵛. 基于微纳操控的石墨烯纳米器件制造基础理论与关键技术研究[D]. 中国科学院沈阳自动化研究所. 中国科学院沈阳自动化研究所. 2014.