A System for Coupled-Field Characterization of Nanomaterials and Nano Devices

纳米材料的表征对于指导纳米材料的合成和基于纳米材料的器件的构建至关重要。该申请人和合作者团队在UofT的安大略先进材料表征中心（OCCAM）的扫描透射电子显微镜（STEM）内共同建立了耦合场NM表征平台。 该RTI应用程序要求扫描电流成像（SCI）系统，以加强耦合场表征NM的电气表征能力。这一要求SCI系统包含以下独特的能力（模式），是必不可少的，我们提出的研究计划。(1)电子束感生电流模式，用于成像半导体纳米材料的少数载流子分布，可以测量其在多场激励下的少数载流子扩散长度;（2）电阻对比成像模式，用于机械负载下纳米材料的非接触电阻率成像;（3）电子束吸收电流模式，用于识别基于NM的膜中的导电路径和导电路径的机械应变引起的变化。SCI系统包括一个现场前置放大器，它增强了目前受到高噪声干扰的I-V测量。为了实现低接触电阻以实现准确表征，该RTI应用还要求使用室内等离子体清洁器来去除（1）电子束引起的碳氢化合物污染和（2）NM合成和转移过程中的残留污染。 所要求的仪器将安装在OCCAM的STEM中，并与我们现有的基础设施集成，形成一个强大的平台，用于NM的耦合场表征。我们的HQP将使用该设备对1D/2D纳米材料和纳米材料基复合薄膜进行原位耦合场表征，并取得令人兴奋的发现。这些设备将用于培训大量的HQP，他们将获得纳米材料合成和表征，纳米力学，精密仪器和纳米器件开发方面的技能。

The characterization of nanomaterials (NMs) is critical for guiding the synthesis of NMs and the construction of NMs-based devices. This team of applicants and collaborators have together established a coupled-field NMs characterization platform inside a scanning transmission electron microscope (STEM) in the Ontario Centre for Characterization of Advanced Materials (OCCAM) at UofT. This RTI application requests a scanning current imaging (SCI) system to strengthen the electrical characterization capabilities for the coupled-field characterization of NMs. This requested SCI system contains the following unique capabilities (modes) that are essential to our proposed research programs. (1) Electron Beam Induced Current mode for imaging the minority carrier profile of a semiconductor NM, which allows the measurement of its minority carrier diffusion length under multi-field excitation; (2) Resistive Contrast Imaging mode for noncontact electrical resistivity mapping of NMs under mechanical loading; (3) Electron Beam Absorbed Current mode for identifying conducting paths and mechanical strain-induced changes of conducting paths in NMs-based films. The SCI system includes an in situ pre-amplifier, which enhances the I-V measurement that currently suffers from high noise interference. To achieve low contact resistance for accurate characterization, this RTI application also requests an in-chamber plasma cleaner to remove (1) electron beam-induced hydrocarbon contamination and (2) residue contamination from NMs' synthesis and transfer process. The requested instruments will be installed in OCCAM's STEM and integrated with our existing infrastructure to form a powerful platform for coupled-field characterization of NMs. Our HQP will use the equipment to conduct in situ coupled-field characterization of 1D/2D NMs and NMs-based composite films and make exciting discoveries. The equipment will be used to train a high number of HQP who will gain skills in nanomaterials synthesis and characterization, nanomechanics, precision instrumentation, and nano device development.