基于微纳操作的三维碳纳米管场效应管组装方法研究

Fabrication of 3D carbon nanotube field effect transistor (CNTFET) is needed to significantly improve the speed of chips, reduce their power consumption and save costs. It has become an issue that needed to be solved in the current electronic industry. The implementation of its structure and function of the 3D CNTFET must rely on reliable assembly technologies of carbon nanotubes (CNTs). However, the existing assembly techniques, such as chemical vapor deposition (CVD), random distribution and dielectrophoresis (DEP), are usually applied for fabrication of the plane CNTFETs, but not for 3D devices. In view of this problem, this project proposes a robotic assembly method based on micro-nano manipulation inside an SEM. Firstly, we study the adhesion mechanism between multi-media and multi-dimensional nanostructures, and aim to improve the electrical reliability of micro-nano devices. Secondly, we explore the mechanism of reliable grasping, fixing and releasing based on every adhesive force, and develop the assembly strategy of micro-nano robots to break through the issue of three-dimensional assembly of nano devices. Finally, this project provides a new way to achieve the 3D assembly of CNTs and the reliable manufacturing of nano devices, and can help to build a new theory on the fussion of micro-nano robotic manipulations and nano device fabrication.

为大幅提升芯片的速度、降低功耗和节约成本，碳纳米管场效应晶体管（CNTFET）的三维搭建是当今电子工业亟需解决的难题。三维CNTFET结构和功能的实现必须依赖于可靠的CNT组装技术。然而，现有的组装技术，如化学气相沉积法、随机分布法、介电泳法等，主要针对平面CNTFET的加工制造，很难应对纳米器件的三维搭建。因此，本项目将围绕纳米器件的三维可靠搭建这一前沿科学问题，研究一种基于扫描电子显微镜（SEM）的机器人化微纳操作组装方法。首先，通过研究多介质、多维度纳米结构间的粘着机理，提高微纳尺度下器件组装的电气可靠性；其次，通过对基于纳米操作机器人的组装策略研究，探索基于各粘着力耦合作用下的可靠抓取、固定与释放机理，突破纳米器件的三维组装这一难题；最终，为CNT的三维灵活组装与纳米器件的可靠制造提供新途径，有助于建立机器人化的微纳操作和纳米器件制造相结合的新理论。

三维纳米器件，如三维碳纳米管场效应晶体管（3D CNTFET）是大幅提升芯片速度、降低功耗的重要方向。然而，三维纳米器件的研发尚处于前期探索阶段，存在的主要问题之一是缺乏灵活可靠的CNT组装技术。本研究提出了一种新型的三维CNTFET结构，并研究了一种基于扫描电子显微镜（SEM）的机器人化微纳操作组装方法。通过对CNT分散方法、CNT与金属表面间的机械粘着和化学粘着机理等的研究，利用AFM悬臂梁实现了单根CNT的自动拾取；为实现CNT/金属间的机械和电学接触特性的定量表征，提出了利用测量悬臂梁弹性形变的方法来表征CNT/FET电极材料（Au）间的机械接触特性，然后分析了两点桥法测量CNT/Au间电学接触特性（接触电阻）的原理，并经实验验证了三维CNTFET组装策略的电气可靠性；通过对组装策略的集成和对策略中基本操作方法的理论分析与实验研究，不仅能够有效地完成CNT的三维组装任务，而且可以用于其他纳米器件的搭建，为纳米器件的可靠制造提供了新途径。