Nucleation Growth and Defect Engineering in Diamond Thin Films

摘要

We studied the chemical nature of the substrate and the role of buffer layers onnucleation and growth of diamond during chemical vapor deposition (hot-filament). The transition metals with partially filled d-atomic orbitals are found to stabilize SP2 bonding which leads to enhanced precipitation of SP2 bonded non-diamond carbon phases such as graphite, amorphous and glassy carbon films. We have shown that by alloying these metals with electron donating elements, it is possible to stabilize SP3 bonding and form diamond film directly on the metallic substrates. Similar studies on nucleation and growth of diamond have been performed using AlN buffer layers. The results from these studies are compared with those obtained using buffer layers. By using these concepts, we have minimized the formation of graphitic layers and improved the adhesion of diamond layers on non-carbide forming metallic substrates.