Fundamentals of thin film growth from the vapor phase and through solid-state reactions

薄膜几乎存在于所有的日常用品中，从眼镜上的抗反射涂层到切割工具上的硬涂层，再到电脑显示器。特别是，它们是微电子和光电子设备的核心：计算机芯片，发光二极管，半导体激光器，太阳能电池，平板显示器，仅举几例。为了满足不断提高的性能要求，单层材料逐渐被复杂的多层材料和异质结构所取代。对更灵活的涂层和器件设计的需求刺激并将继续推动具有可定制性能的人工纳米结构材料的发展。“薄膜”产业正在快速扩张。2008年，它代表了100 G$的市场，终端市场规模为2300 G$。预计到2030年，这两个数字将分别增加到400元和7000元。虽然信息技术一直被认为是一个主要的应用领域，但预计最引人注目的收益将出现在能源、交通、环境和卫生领域。**我们的最终目标是详细了解薄膜生长过程中发生在表面和界面上的原子过程，以便生产具有预定性能的材料。我们的第一个目标是研究石墨烯从气相生长的局部细节，以优化其制造。石墨烯是一种单层碳原子平面，是一种具有独特性能的二维材料。石墨烯是透明的，并表现出良好的电导率和导热性，例如，它被设想为太阳能电池和显示器的可调谐和透明电极。我们试图对各种气体种类和生长参数对石墨烯形成和蚀刻的不同影响进行详细的局部理解。我们想要确定氧化杂质攻击新形成的石墨烯岛的位置，并了解所涉及的化学物质的催化作用。**我们的第二个目标是了解织构遗传在晶体生长中的作用，并通过设计来精确控制非均质材料和亚稳相的形成。织构——在给定材料中晶粒取向的分布——对薄膜性能有深远的影响。例如，它会影响涂层的硬度、薄导体中的电迁移阻力以及界面的稳定性。更具体地说，我们将研究在最先进的集成电路中用于与晶体管形成接触的固态反应。我们将着重于通过使用掺杂剂和合金元素来调整所需反应膜的性质来操纵该反应。在一组互补的实验中，我们将利用织构继承来形成自旋电子学的非均质磁性/半导体薄膜。**我们的研究项目力求在纳米材料领域取得最高的科学和技术影响。我们预计我们的研究结果将广泛应用于薄膜合成领域的许多应用领域，例如（光电）电子器件制造和材料表面改性。我们相信，这些结果将导致在这些以及相关领域进行意义深远的新研究。培养高素质人才是我们研究的重要组成部分，研究生和博士后将获得深入的薄膜生长，表面物理，材料物理和表征方面的知识，为他们在加拿大大学，国家实验室和行业的研发事业做好准备。

Thin films are found in nearly all everyday products, from antireflective coatings on glasses to hard coatings on cutting tools to computer displays. In particular, they are the core of micro- and optoelectronic devices: computer chips, light emitting diodes, semiconductor lasers, solar cells, flat panel displays, just to name a few. In answer to continuously increasing demands for improved performance, single layers have gradually been replaced by complex multilayers and heterostructures. The demand for more flexibility in coating and device design has stimulated and continues to drive the development of artificially nanostructured materials with tailorable properties. The "thin film" industry is expanding at a rapid pace. It represented a market of 100 G$ with an end-market size of 2300 G$ in 2008. These numbers are forecast to increase to 400 G$ and 7000 G$, respectively, by 2030. While information technology has always been recognized as a major application sector, the most spectacular gains are predicted to be in energy, transportation, environment, and health.**Our ultimate goal is to develop a detailed understanding of atomic processes occurring on surfaces and at interfaces during the growth of thin films in order to produce materials with predetermined properties. Our first objective is to investigate the local details of the growth of graphene from the vapor phase in order to optimize its fabrication. Graphene - a monolayer plane of carbon atoms - is a bidimensional material with unique properties. Being transparent and exhibiting good electrical and thermal conduction properties, graphene is envisioned, for example, as a tunable and transparent electrode for solar cells and displays. We seek to develop a detailed local understanding of the distinct effects of the various gaseous species and growth parameters on the formation and etching of graphene. We want to identify the sites where oxidizing impurities attack newly formed graphene islands and to understand the catalytic effects of the chemical species involved.**Our second objective is to understand the role of texture inheritance in crystal growth, and to progress towards the precise control of the formation of heterogeneous materials and metastable phases by design. Texture - the distribution of grain orientations in a given material - has a profound effect on film properties. It influences, for example, the hardness of coatings, the resistance to electromigration in thin conductors, and the stability of interfaces. More specifically, we will investigate the solid state reaction used to form contacts with transistors in the most advanced integrated circuits. We will focus on manipulating this reaction through the use of dopants and alloying elements for tuning the properties of the desired reacted films. In a complementary set of experiments, we will exploit texture inheritance for forming heterogeneous magnetic/semiconductor films for spintronics.**Our research program strives for the highest scientific and technological impact in the area of nanoscale materials. We anticipate that the results of our research will be broadly applicable in the field of thin film synthesis in a large number of application areas including, for example, (opto)electronic device fabrication and surface modification of materials. We are confident that the results will lead to far-reaching new research in these, as well as related, areas. Training of highly qualified personnel is an integral part of our research as graduate students and postdoctoral fellows will acquire an in-depth knowledge of film growth, surface physics, as well as materials physics and characterization that prepares them perfectly for R&D careers in Canadian universities, national laboratories, and industries.