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

点击翻译按钮获取中文摘要

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 In answer to continuously increasing demands for improved performance, single layers have gradually been replaced by complex multilayers and heterostructures.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.