Thin film SiC epitaxy on Si(111) from acetylene precursor

A promising route for the production of SiC on Si surfaces exploits the use of small pi-bonded hydrocarbons, like acetylene, as carbon source. This choice in fact, allows maintaining the growth temperatures well below 1000 C. Starting from the hydrogenated Si(111)(1 x 1) surface can be a way to keep the Si substrate always below 800degreesC. In this way, however, to obtain a SiC film composed of large crystallites is not straightforward. We report on the epitaxial growth of 3C-SiC thin films on the Si(111)-(7x7) surface, obtained by dosing acetylene at 750degreesC. The growth was been followed by means of LEED, X-ray photoemission and Auger spectroscopy, as well as by high-resolution electron-energy loss spectroscopy. HREEL spectra show very strong features related to the SiC Fuchs-Kliewer phonon (and its replicas), XPS peaks show losses associated to the SiC bulk plasmon, while the LEED pattern is that of the 3C-SiC, confirming the crystalline character of the epitaxial film. The mean film thickness, as measured by ex-situ TEM, is of few hundreds Angstrom.