In-situ Incorporation of Lithium and Nitrogen into CVD Diamond Thin Films

Abstract

ABSTRACTExperiments were performed to incorporate Li and N simultaneously into the diamond lattice during hot-filament chemical vapour deposition in an attempt to produce n-type semiconducting diamond with useful electronic characteristics. Microcrystalline diamond films were grown using a mixture of methane/ammonia/hydrogen gases with tantalum as the filament. The Li was added by placing crystals of lithium nitride (Li3N) on the substrate and allowing them to melt and then slowly diffuse into the film. SIMS depth profiles showed that this process produced high levels of Li and N (0.05% - 0.5%) situated in the same region within the diamond film. The crystallinity and morphology of diamond crystals produced were confirmed using laser Raman spectrometry and scanning electron microscopy.