NOVEL SYNTHETIC ROUTES TO CARBON-NITROGEN THIN-FILMS

New unimolecular carbon-nitride precursors such as C3N3F2N(SiMe3)2 and C3N3Cl2N(SiMe3)2 were synthesized and used to deposit thin films of composition C3N4-C3.2N4, the highest nitrogen content observed in C-N solids. The films were formed by the thermal decomposition of the precursors via elimination of SiMe3F and SiMe3Cl at 400-500-degrees-C. Film thicknesses between 1200 and 4000 angstrom were deposited on (100) Si, graphite, beryllium, and SiO2, and were extensively characterized for composition and chemical purity using RBS, energy-dispersive X-ray analysis, and SIMS. The material was amorphous as indicated by X-ray diffraction. IR, EELS, and C-13 NMR reveal substantial sp2 hybridization in both the carbon and the nitrogen. This material should be an excellent precursor for the high-pressure synthesis of C3N4, the highly sought structural and compositional analog of Si3N4.