Silicon carbide (SiC) films have been successfully deposited on various substrates by oligomer thermal chemical vapor deposition (OTCVD) from a novel, halogen free, oligomer precursor family of polysilyenemethylenes (PSMs) called SP-4000. The high quality films were grown at substrate temperatures in the range of 620°C to 850°C and at process pressures in the range of 1 - 200Torr. SP-4000 is a silicon carbide precursor with formula [-SiH2-CH2-]n, n=2-8, composed of an alternating silicon and carbon backbone with hydrogen side groups. Depositions on Si and graphite substrates yielded SiC films with Si/C ratios in the range 1.1 to 1.2 and thicknesses in the range 0.3 to 50μm.
Structural and chemical characterizations were performed by Auger electron spectroscopy (AES), x-ray diffraction (XRD), nuclear reaction analysis (NRA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM).
The SiC coatings deposited at substrate temperatures below 1100°C were found to be amorphous. Ex-situ, post deposition annealing in inert gas ambient above 1100°C converted the SiC films to a polycrystalline phase.