Sputter Deposition And Characterization Of Molybdenum Disulfide Thin Films

The objective of this work is to prepare Molybdenum thin films to be used as efficient back contact materials and utilize characterization techniques for the investigation of the growth as well the physical properties of Mo thin films deposited through DC-plasma magnetron sputtering on soda lime glass substrate. The effects of process parameters, such as Ar pressure, deposition power and substrate temperature, on the properties of the deposited films have been studied. These process parameters were optimized to get high conductivity Mo thin films to be used in CIGS based thin films solar cells as a back contact.

Two-dimensional materials, or materials that are only one atomic layer thick, have seen much research in recent years because of their interesting electrical properties. The first of these materials, graphene, was found to have incredible electrical properties but lacked a bandgap in intrinsic films. Without a bandgap, graphene cannot create transistors that can be shut off. Molybdenum disulfide, however, is a two-dimensional semiconductor with a large bandgap. The main issue of molybdenum disulfide is that synthesized films are a much lower quality than their exfoliated counterparts. For molybdenum disulfide to be able to be used practically, a method of synthesis must be found that can reliably create quality large area monolayer films. In this thesis, three methods of molybdenum disulfide film synthesis are presented. Methods implemented used a tube furnace as a chemical vapor deposition system to evaporate source materials to synthesize thin films of molybdenum disulfide. An exploration into the different synthesis parameters shows optimal conditions for these specific methods. Then a discussion of these different methods is presented by judging films grown by using these methods on relevant criteria. This work shows methods to synthesize large area, polycrystalline, small grain, multilayer films, both intrinsic and doped, and to synthesize small area, single crystal and polycrystalline, monolayer films of molybdenum disulfide.

Molybdenum nitride thin film was deposited on silicon wafer by the reactive sputter deposition. Single phase?6Mo 2 N thin film was obtained with N 2 /(Ar+N 2) flow ratios in sputtering gas varying from 10% to 30% whereas an amorphous structure was obtained at N2/(Ar+N2) flow ratios of 50%. The deposition rate of the molybdenum nitride thin film varies significantly as nitrogen partial pressure in sputtering gas increases. A decrease in peak intensity along with peak shift and broadening was observed in X-ray diffraction spectra as the nitrogen partial pressure sputtering gas increased. The XPS analysis of the as-deposited thin films shows that the Mo 3d 3/2, Mo 3d 5/2 and Mo 2p 3/2 peak gradually shift to the higher binding energy direction as nitrogen partial pressure is increasing. The intensity of N 1s peak also increase with increasing nitrogen partial pressure. Although the XRD examination shows no evidence of long range order of the phase structure for the amorphous thin film sputtered at 50% N 2 /(Ar+N 2) flow ratio, the existence of Mo6N bond in the film was confirmed by XPS examination. The nitrogen partial pressure in the sputtering gas was found to have significant influence on the surface morphologies and cross section structures of the thin film. Thermal annealing of the amorphous thin film in a nitrogen atmosphere revealed that the film could survive 700ʻC,5min thermal annealing without obvious crystallization but failed after 800ʻC,5min thermal annealing, in which the crystalline?-Mo 2 N and h6MoSi 2 phases were observed simultaneously.

Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 39 (thesis year 1994) a total of 13,953 thesis titles from 21 Canadian and 159 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 39 reports theses submitted in 1994, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.

This thoroughly updated new edition includes an entirely new team of contributing authors with backgrounds specializing in the various new applications of sputtering technology. It forms a bridge between fundamental theory and practical application, giving an insight into innovative new materials, devices and systems. Organized into three parts for ease of use, this Handbook introduces the fundamentals of thin films and sputtering deposition, explores the theory and practices of this field, and also covers new technology such as nano-functional materials and MEMS. Wide varieties of functional thin film materials and processing are described, and experimental data is provided with detailed examples and theoretical descriptions. A strong applications focus, covering current and emerging technologies, including nano-materials and MEMS (microelectrolmechanical systems) for energy, environments, communications, and/or bio-medical field. New chapters on computer simulation of sputtering and MEMS completes the update and insures that the new edition includes the most current and forward-looking coverage available All applications discussed are supported by theoretical discussions, offering readers both the "how" and the "why" of each technique 40% revision: the new edition includes an entirely new team of contributing authors with backgrounds specializing in the various new applications that are covered in the book and providing the most up-to-date coverage available anywhere