Apparatus for studying the structure and evolution of atomically-ordered domain boundaries, kinks and vertexes

用于研究原子有序域边界、扭结和顶点的结构和演化的装置

• 批准号: 389553-2010
• 负责人: McLean, Alastair
• 金额: $ 4.75万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=464663
• 关键词: Apparatus; studying; structure; evolution; atomically

In many classes of electronic materials, such as polycrystalline Si or high-k dielectrics, properties such as solar cell efficiency or breakdown field depend on the size and spatial arrangement of crystalline grains and the distribution of interfaces (microstructure). Materials are frequently annealed to initiate micro-structural transformation via re-crystallization and grain growth. Although, there is a large literature on grain grown and grain coarsening, in lieu of detailed crystallographic information about interfaces and interface energies, theoretical models normally assume that interface energies are isotropic. To go beyond this, it is necessary to classify interfaces according to their microstructure and this could lead to a quantitative understanding of the relationship between processing, structure and material properties. Consequently, we are excited by the fact that we have discovered a two-dimensional analog of a three-dimensional electronic material that has a highly anisotropic distribution of interfaces (domain boundaries) that is amenable to detailed investigation at the atomic level. Specifically, we have developed a way of growing a Ge film on an atomically flat Si surface so that it contains crystalline domains separated by atomically ordered boundaries. Using this model system it is possible to study: the distribution of domains, the distribution of boundaries, the atomic structure of boundaries and the temporal evolution of boundaries, kinks and vertexes. To take full advantage of this system we require electronics that will allow us to perform tunneling and force microscopy simultaneously. This will allow us accurately determine the position of atoms in the boundary region and also discriminate between Si and Ge atoms in many cases. These studies will provide atomic-level information about the physical factors that determine the anisotropic distribution of boundaries and the growth of domains in well-characterized model system. This apparatus will also provide novel training opportunities for six highly qualified personnel/year.

在许多类别的电子材料中，例如多晶硅或高 k 电介质，太阳能电池效率或击穿场等特性取决于晶粒的尺寸和空间排列以及界面（微观结构）的分布。材料经常进行退火，以通过再结晶和晶粒生长引发微观结构转变。尽管有大量关于晶粒生长和晶粒粗化的文献，但理论模型通常假设界面能是各向同性的，而不是有关界面和界面能的详细晶体学信息。为了超越这一点，有必要根据界面的微观结构对其进行分类，这可以导致对加工、结构和材料性能之间关系的定量理解。因此，我们感到兴奋的是，我们发现了三维电子材料的二维模拟，该材料具有高度各向异性的界面（域边界）分布，适合在原子水平上进行详细研究。具体来说，我们开发了一种在原子级平坦的硅表面上生长Ge薄膜的方法，使其包含由原子有序边界分隔的晶域。使用该模型系统可以研究：域的分布、边界的分布、边界的原子结构以及边界、扭结和顶点的时间演化。为了充分利用该系统，我们需要能够同时执行隧道和力显微镜的电子设备。这将使我们能够准确地确定边界区域中原子的位置，并在许多情况下区分 Si 和 Ge 原子。这些研究将提供有关物理因素的原子级信息，这些物理因素决定了特征良好的模型系统中边界的各向异性分布和域的增长。该设备还将每年为六名高素质人员提供新颖的培训机会。