COMPARATIVE-STUDY OF DECOMPOSITION BY METAL-ORGANIC CHEMICAL VAPOR-DEPOSITION OF TETRAETHYLSILANE AND TETRAVINYLSILANE

Two precursors, tetraethylsilane (TESi) and tetravinylsilane (TVSi) were used to prepare SixC1-x coatings by chemical vapour deposition. The solid phase was analysed by transmission electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy and Raman spectroscopy. The decomposition yield vs. temperature (using He or H-2 carrier gas) and the concentrations in the gas phase were followed by gas-phase chromatography. TVSi pyrolysis occurred at low temperatures and led to carbon-rich SixC1-x deposits, while TESi decomposition began at higher temperatures to give almost stoichiometric coatings. H-2 carrier gas reduced the percentage of carbon. Correlations between the gas phase and the solid phase showed that the structure of the organometallic molecule is the determining factor in the thermal behaviour of the precursor.