Picometer Probes for Defects in Nanostructures

用于纳米结构缺陷的皮米探针

• 批准号: RGPIN-2014-04684
• 负责人: Kavanagh, Karen
• 金额: $ 4.3万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632996
• 关键词: Picometer; Probes; Defects; Nanostructures

Nanometer scale wires (nanowires) made out of almost every material has attracted tremendous attention over the past ten years. A major reason is their ease of growth, and the many demonstrations of novel devices and unique properties. Intriguing are the quantum size effects whereby materials with nanoscale dimensions develop different properties compared to their bulk. The increased speed and efficiency of two-dimensional quantum devices made with semiconductors, such as silicon and gallium arsenide, has already been driving progress in the electronics industry for decades. The growth of three-dimensional, semiconductor nanowires, is enabling further developments in novel device and circuit design. Nanowires are too tiny to be seen with an optical microscope and therefore, many of their structural properties have been revealed through various types of electron microscopies. But their most important properties are controlled by their atomic point defects - missing atoms, impurity atoms, or atoms in between the rows of the crystalline matrix. In the research proposed here, we will apply picoscale probes to determine the complete atomic picture of novel semiconductor nanowires. In particular, we will apply the latest in aberration-corrected transmission electron microscopy (new facility at U. Victoria). This machine has a resolution of 35 picometers, capable of peering into the spaces between atoms. We will apply the associated technique, electron holography, to map the electrical activation in nanowires and measure magnetic fields at nanowire ferromagnetic contacts. We will establish a transmission helium ion microscopy facility and use coherent helium atoms to probe bulk and surface defects. Helium ions and neutral atoms are 35 - 90 picometers in diameter, easily capable of passing in between rows of atoms. We will collaborate to access atom probe tomography, a technique that can map the elemental identity of every atom within a nanowire. We will complement these tools with existing macroscopic characterization techniques, including in-situ electrical and optical excitation, scanning tunneling microscopy, and ballistic electron emission microscopy. Seeing point defects and their movements directly in materials is becoming a possible dream. The proposed research program will help confirm theoretical predictions about their presence in novel semiconductor nanowires. Identification is fundamental to the control of nanowire electronic properties. New understanding invariably leads to innovation, engagement with existing Canadian companies, and eventually to the establishment of new industries in Canada. If successful, the novel semiconductor nanostructures investigated in this research will impact the telecommunications, advanced lighting, solar energy, and information technology industries in Canada and elsewhere. Three-dimensional geometries are critical to continued increases in integrated circuit densities a billion dollar industry which Canada plays a roll. The proposed research is internationally cutting edge, an activity that easily attracts new students and post doctoral fellows to the field.

在过去的十年里，几乎由每种材料制成的纳米尺度的线（纳米线）吸引了巨大的关注。一个主要原因是它们易于生长，以及许多新设备和独特性能的展示。有趣的是量子尺寸效应，即纳米尺度的材料与其体积相比具有不同的性质。用硅和砷化镓等半导体制成的二维量子器件的速度和效率的提高，已经推动了电子工业几十年的进步。三维半导体纳米线的生长正在推动新型器件和电路设计的进一步发展。纳米线太小，无法用光学显微镜观察到，因此，它们的许多结构特性已经通过各种类型的电子显微镜揭示出来。但它们最重要的性质是由它们的原子点缺陷控制的-缺失的原子，杂质原子或晶体基质行之间的原子。在这里提出的研究中，我们将应用皮尺度探针来确定新的半导体纳米线的完整原子图像。特别是，我们将应用最新的像差校正透射电子显微镜（新设施，在美国。维多利亚）。这台机器的分辨率为35皮米，能够窥视原子之间的空间。我们将应用相关的技术，电子全息，映射在纳米线的电激活和测量纳米线铁磁接触的磁场。我们将建立一个透射氦离子显微镜设备，并使用相干氦原子探测体和表面缺陷。氦离子和中性原子的直径为35 - 90皮米，能够很容易地在原子行之间通过。我们将合作访问原子探针断层扫描，一种可以映射纳米线内每个原子的元素身份的技术。我们将补充这些工具与现有的宏观表征技术，包括原位电和光激发，扫描隧道显微镜，弹道电子发射显微镜。直接在材料中观察点缺陷及其运动正在成为一个可能的梦想。拟议中的研究计划将有助于证实关于它们存在于新型半导体纳米线中的理论预测。识别是控制纳米线电子性质的基础。新的理解必然会导致创新，与现有的加拿大公司合作，并最终在加拿大建立新的产业。如果成功，这项研究中研究的新型半导体纳米结构将影响加拿大和其他地方的电信，先进照明，太阳能和信息技术行业。三维几何结构对于集成电路密度的持续增加至关重要，这是加拿大发挥作用的十亿美元产业。拟议中的研究是国际前沿的，很容易吸引新的学生和博士后研究人员到该领域的活动。