X-ray photoelectron spectroscopy and Raman spectroscopy investigations of amorphous Sisub(x)Csub(1-x)(H) coatings obtained by chemical vapour deposition from thermally labile organosilicon compounds

Thermal decomposition of organosilicon molecules was carried out in order to obtain amorphous coatings with variable silicon and carbon contents. The authors selected four molecules: two cyclic molecules, sila-5-spiro[4.4]nona-2,7-diene and dimethyl-2,7-sila-5-spiro[4.4]nona-2,7-diene, and two non-cyclic molecules, tetrapropargylsilane and tetraethynylsilane. Classical chemical vapour deposition (CVD) apparatus was used and the nature of various influences was studied. The coatings were investigated by X-ray photoelectron spectroscopy and micro Raman spectrometer analysis. The coatings have the general formula Sisub(x)Csub(1-x)(H), where x varies from 0.24 to 0.82 (depending on the molecule and the decomposition temperature). The correlations between the properties of the solid phase (coating) and the gas phase (decomposition byproducts) in the CVD reaction permit an understanding of the decomposition. The coating composition is related to the structure of the starting molecule. (Auth.)