| his thesis is concerned with the internal structure of diamond thin films prepared by the microwave plasma enhanced chemical vapor deposition (MPECVD) and its correlations with the deposition processes and the resulting film properties. Various internal structural features including bulk graphite inclusions, interfaces and structural defects, the parametric deposition processes, the noble gas-involved plasma chemistry, and the oxidation properties of diamond films are investigated. The results contribute to the general understanding of the nature of the MPECVD processes of diamond film preparation and provide guidelines for designing experiments to deposit tailored structures of diamond films required for particular applications.;The diamond growth under CVD conditions is a highly selective process with narrow and various sets of optimum conditions depending on which film characteristic or property, such as maximum growth rates, minimum structural defects, large area uniform coverages, etc., is being optimized. The optical emission spectroscopy of the methane-hydrogen-noble gas plasmas indicates that, although hydrogen is the main dilution gas reacting actively in the diamond deposition process, the noble gases also are active in deposition by creating additional excited atom-molecule or ion-molecule reactions. The internal structure of CVD diamond films is quite complex. They are polycrystalline in nature with varying grain sizes and orientations. Typically, the... |
