Synthesis of high quality crystalline C-N films on silicon

High quality crystalline C-N films have been synthesized via hot filament chemical vapor deposition using a gas mixture of nitrogen and methane. Scanning electron microscopy images show that a high density of crystalline clusters has been achieved. The clusters are composed of small columnar crystals (20-200 nm across) with hexagonal facets. Energy dispersive X ray analysis indicates a relative nitrogen:carbon composition of 1.30-2.5. X ray diffraction results indicate the films composed of beta- and alpha-C3N4 phases. Together with transmission electron microscopy analyses, we suggest that an interfacial layer C3-xSixN4 is formed between the silicon substrate and the crystalline carbon-nitride films.