alpha-SiC layers grown on silicon via nano-sized silicon nitride precursorroute

alpha-SiC thin layers were successfully grown on silicon (111) by pyrolysis of the organic liquid dip-coating films and polyimide Langmuir-Blodgett (L B) films containing nanometer sized amorphous silicon nitride powders (NASN P) at 900-1000 degrees C in vacuum. The products were characterized by X-ra y diffraction (XRD), infrared absorption (IR) and Raman spectra, the result s of which strongly support the formation of preferred orientated 4H-SiC in the layers by pyrolysis of LB films containing NASNP. Based on the IR spec tra of samples pyrolyzed at different temperatures and the computed values of the Gibbs free energy changes of the reactions, the mechanism of formati on of alpha-SiC is discussed. (C) 1999 Elsevier Science S.A. All rights res erved.