Crystalline beta-C3N4 synthesized by MPCVD

Carbon nitride films were grown on Si and Pt substrates by microwave plasma chemical vapor deposition (MPCVD) method. Scanning electron microscope (SE M) observations show that the films deposited on Si substrates consisted of densely populated hexagonal crystalline rods. Energy dispersive X-ray (EDX ) analyses show that N/C ratios of the rods were in the range of 1.0 to 2.0 depending on deposition condition. X-ray diffraction experiments show that the films consisted of crystalline phase beta-C3N4 Comparison with films g rown on Pt substrate show that the main X-ray diffraction peaks of beta-C3N 4 are existed in films deposited on both substrate. XPS study showed that c arbon and nitride atoms are covalent bounded to each other. IR results show that the film is predominantly C-N bonded. Raman measurement showed charac teristic peaks of beta-C3N4 in the low wave number region. Temperature depe ndent growth experiments show that the amount of Si3N4 in the films grown o n Si substrates can be significantly reduced to negligible amount by contro lling the substrate temperature. (C) 1999 Kluwer Academic Publishers.