NER: Focused Ion Beam (FIB) Micromachining and Advanced Characterization of Carbon Nanotube-Metal Junctions

该项目是对NSF 01-157类纳米科学与工程倡议的响应。本研究的目的是发展利用高分辨电子显微镜、电子能量损失谱和能量过滤电子显微镜表征碳纳米管-金属结的局域原子级结构和化学界面的方法。聚焦离子束微加工将被用来在碳纳米管(CNT)上制造铂金属接触，并进行局部样品横截面以供进一步的透射电子显微镜分析。这项研究的目标有三个方面：(1)发展纳米尺度的表征技术，以便在原子水平上了解FIB辅助的金属沉积对碳纳米管/铂界面结构和化学的影响；(2)开发用于选择性(局域)高分辨率透射电子显微镜和碳纳米管-金属结的电子能量损失谱的样品制备技术；(3)开发原子水平控制互扩散和形貌的可重复金属接触制备技术。这项研究将把纳米对象/金属结的研究推进到原子水平上对界面结构和化学的理解。碳纳米管/金属局域截面高分辨率化学和结构分析的优化方法的发展将有助于大多数纳米物体和未来的纳米器件的研究。具有已知性质的碳纳米管/金属结的受控纳米制造将有助于对从化学传感器到场效应晶体管等各种应用的纳米材料和结构进行可靠的电学测试，从而使制造出服务于人们日常生活的新器件成为可能。两名研究生将直接参与该项目，获得诸如透射电子显微镜、电子能量损失谱和FIB微聚合等高级表征技术方面的知识。该计划产生的专业知识将直接用于教育过程，教授当前和未来的科学家/技术专家。国际和平研究所将组织和举办科学研讨会，将新数据纳入研究生级课程，以促进知识和制定的方法的传播。

This project was received in response to Nanoscale Science and Engineering initiative, NSF 01-157, category NER. The goal of the research is to develop the methodology of localized atomic-level structural and chemical interfacial characterization of carbon nanotube-metal junctions using high resolution transmission electron microscopy (TEM), electron energy loss spectroscopy and energy filtered TEM. The Focused Ion Beam micromachining will be used to fabricate platinum metal contacts onto carbon nanotubes (CNTs), and also for localized specimen cross-sectioning for further TEM analysis. The objectives of the study are threefold: (1) advancement of nanoscale characterization techniques to achieve an understanding of the effects of FIB-assisted metal deposition on the CNT/Pt interfacial structure and chemistry at atomic level; (2) development of a specimen preparation technique for selective (localized) high-resolution TEM and electron energy loss spectroscopy of CNT-metal junctions; (3) development of reproducible metal contact fabrication technique with atomic-level control of inter-diffusion and morphology. The research will advance the nanoobject/metal junction studies to the atomic-level of understanding of the interfacial structure and chemistry. Development of optimized methodology of CNT/metal localized cross-sectioning technique for high-resolution chemical and structural analysis of the junction will be useful for studies of the majority of nanoscale objects and future nano-devices. Controlled nano-fabrication of CNT/metal junctions with known properties will facilitate the reliable electrical testing of the nanosized materials and structures for variety of applications ranging from chemical sensors to field effect transistors, thus enabling fabrication of new devices to serve people in their everyday life. Two graduate student will be directly involved in the program gaining knowledge in such advanced characterization techniques as transmission electron microscopy, electron energy loss spectroscopy, and FIB micromashining. The expertise generated by this program will be utilized directly in the educational process to teach the current and future scientists/technologists. The PI will organize and carry out scientific seminars, will incorporate new data into the graduate level courses to facilitate the dissemination of knowledge and the developed methodology.