Comparative study of decomposition by metal-organic chemical vapour deposition of tetraethylsilane and tetravinylsilane

Abstract

Two precursors, tetraethylsilane (TESi) and tetravinylsilane (TVSi) were used to prepare Si_xC_{1 –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 H₂ 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 Si_xC_{1 –x} deposits, while TESi decomposition began at higher temperatures to give almost stoichiometric coatings. H₂ 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.