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题名	基于原子力显微镜(AFM)的纳米焊接方法研究
作者	刘增磊
学位类别	博士
答辩日期	2014-05-17
授予单位	中国科学院沈阳自动化研究所
导师	王志东 ; 董再励
关键词	纳米焊接 原子力显微镜 针尖材料沉积 场蒸发 纳米器件
其他题名	Nanosoldering Research Based on Atomic Force Microscope
学位专业	模式识别与智能系统
中文摘要	纳米制造是纳米技术的核心内容之一，纳米制造能力直接反映了纳米技术的发展水平。纳米尺度的焊接加工是实现纳米制造的关键技术环节。本论文的研究内容以国家自然科学基金支持项目“基于原子力显微镜(AFM)微观电场的纳米焊接方法研究”(61106109)及辽宁省自然科学基金支持项目“利用原子力显微镜微观电场进行纳米焊接的方法研究”(201102229)为依托，以纳米器件加工为应用背景，基于原子力显微镜(AFM)操控技术，开展了微观电场条件下纳米焊接加工的理论方法研究。研究内容主要包括以下四个方面： (1) AFM微观电场与场蒸发加工理论分析 基于场蒸发理论，运用分子动力学分析方法，构建了AFM微观电场的场蒸发模型，进行了场蒸发沉积加工实验验证，为纳米尺度金属原子蒸发焊接加工提供了理论依据。运用有限元仿真分析方法，开展了外加电压条件下，AFM探针与样品间的微观电场分布研究，分析了电压、间距以及湿度等因素对电场分布的影响，建立了外加电压与微观电场强度的关系。通过仿真计算和实验研究，验证了焊接点沉积是场蒸发的过程而不是热蒸发的过程。 (2) 导电探针的金属镀层加工技术研究 针对场蒸发沉积加工对探针金属镀层的消耗问题，开展了基于离子溅射原理与相关技术的探针金属镀层加工方法研究。研究分析了金属镀层厚度对场蒸发沉积效果的影响，并通过实验建立了针尖镀层厚度与溅射加工时间的关系，给出了适宜探针沉积加工的镀层厚度与溅射参数。 (3) AFM场蒸发沉积的重复性与精度控制方法研究 针对微观场蒸发沉积加工可控性差的问题，开展了不同AFM操控模式的焊接方法研究，分析了探针-样品间距与加工电流对沉积的影响，建立了基于针尖-样品距离控制的电流诱导沉积加工方法，并通过实验研究，验证了上述方法的有效性。在此基础上，实现了纳米线、纳米坑等结构的加工实验，丰富了AFM电场加工手段。 (4) AFM场蒸发沉积焊接的效果分析与实验研究 运用检测分析手段，开展了对沉积点的元素成分、电学性能和力学性能三个方面实验研究。通过能谱分析仪检测，证明沉积点成分与针尖镀层金属相同；通过加工石墨烯电极并在石墨烯电极之间沉积纳米点，验证了沉积点的导电性；通过AFM操作，验证了沉积点具有良好的物理固定能力。基于上述研究，进行了碳纳米管晶体管(CNTFET)的焊接实验研究，实验表明，焊接有效降低了接触电阻，提高了该器件的导电性能。 本论文研究的意义在于研究探索一种基于场蒸发机理的具有良好可控性的低成本纳米焊接方法，为纳米器件与纳米结构的加工制造提供具有重要现实意义的纳米尺度焊接加工技术以及相关理论分析方法。
索取号	TB383/L76/2014
英文摘要	Nanofabrication is one of the core content of nanotechnology. Nanomanufacturing capability directly reflects the developing level of nanotechnology. Nanoscale welding process is a key technical aspect of nanomanufacturing. The research of this thesis is supported by National Natural Science Foundation of China project “Nanosoldering research based on microscopic electric field of AFM”(61106109) and Natural Science Foundation of Liaoning province project “Nanosoldering research using microscopic electric field of AFM”(201102229). Aiming at promoting nanodevice fabrication, this thesis carries out intensive research on nanosoldering method using AFM nanooperation technique. This thesis mainly includes the following four contents: (1) Theoretical analysis for the nanoscale electric field and field emission of AFM Based on field emission theory, field emission model of AFM with nanoscale electric filed is deduced from the perspective of molecular dynamics, and the model is testified by experiments. This provides theoretical instructions for field emission deposition. In addition, the nanoscale electric field according to applied voltage around AFM tip is simulated by finite element method (FEM) and impact on field distribution is discussed by parameters such as voltage, tip-substrate distance and humidity. The relationship between applied voltage and electric field strength is derived from simulation. According to simulation and experimental measurement, AFM deposition assisted by electric filed is a process of field emission rather than thermo evaporation. (2) Discuss on metal-coating process to fabricate conducting AFM probe Field emission deposition causes continuous consumption of the metal coated on AFM tip, so the process for coating AFM probe is explored using an ion sputtering machine. The impact on field emission deposition by the thickness of coated metal is discussed and the relationship between the thickness of the coated metal and the sputtering time is build by experiments. Consequently proper thickness of coated metal with relative parameters for ion sputtering is given. (3) Researches on accurate and repeatable AFM filed emission deposition method Due to the awful controllability of field emission deposition, deposition under different AMF mode is discussed, and impact on deposition by tip-sample distance and current is analyzed. So a current induced deposition method with tip-sample distance control is established and experiments testify that the method is effective. In addition, nanoline and nanopit are successfully fabricated during exploring field emission deposition, which broadens the operations of AFM assisted by electric field. (4) Experimental analysis on soldering effect of AFM deposition The element, electrical properties and mechanical properties of deposited nanodots are measured respectively. Spectrum analyzer measurement shows that the element of the deposited dot is the same with the coated metal on the probe tip; the conductivity of deposited nanodots is testified by depositing a nanodot on graphene electrodes; the mechanical properties of deposited nanodots are testified by AFM pushing. Based on the above studies, a CNTFET is soldered. Experimental results shows that the contact resistances of the CNTFET are reduced effectively and the conductivity of the CNTFET is improved. The significance of this thesis is to explore a controllable and low cost nanosoldering method, which can provide meaningful technical soldering solution and relative theory analysis for nanodevice and nanostructure fabrication.
语种	中文
产权排序	1
页码	102页
分类号	TB383
内容类型	学位论文
源URL	[http://ir.sia.ac.cn/handle/173321/14837]
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	刘增磊. 基于原子力显微镜(AFM)的纳米焊接方法研究[D]. 中国科学院沈阳自动化研究所. 2014.

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