Growth, Characterization and Device Development in Monocrystalline Diamond Films

摘要

Highly oriented diamond has been grown on (100) Ni substrates by the hot filamentchemical vapor deposition method. Epitaxial nuclei were obtained by diamond powder seeding and a subsequent high-temperature annealing process. Real time, in situ laser reflectometry was developed to monitor changes in surface morphology observed during the high temperature annealing since the timing of the process was crucial for the achievement of a high degree of orientation and a high density of diamond nuclei. characteristic features observed in the intensities of reflected and scattered light were interpreted by comparison with scanning electron micrographs of the samples quenched at sequential stages of the process. It was concluded that the scattered light signal can be effectively used as a process steering parameter. Auger spectroscopy showed that up to 6 at% of the C was dissolved in the Ni surface layer. The investigation of interfacial microstructures and phases involved by transmission electron microscopy revealed the formation of Ni4C already in the early stages of nucleation. This phase was manifested as coherent precipitates and is believed to have been the precursor for diamond nucleation. Perfectly epitaxial diamond was grown by this process.