Thin films of silicon oxynitrocarbide (SiONC) have been deposited on silicon by polymer-source chemical vapor deposition (PSCVD) using poly (dimethylsilane). The chemical and structural composition of these films have been investigated using Fourier transform infrared spectroscopy, elastic recoil detection spectroscopy (ERD), and X-ray photoelectron spectroscopy (XPS). ERD depth-profile analysis revealed a homogeneous film with uniform bulk concentrations for silicon, carbon, nitrogen, and oxygen. XPS analysis showed that nitrogen, oxygen, and carbon were all uniquely bonded to silicon. The oxygen nitrogen bonds were not observed in these films. XPS analysis also revealed the presence of carbon-carbon bonds associated with graphite. It was shown that the graphitic phase is limited to the surface layer of these films, and is due to unintentional carbonization at the end of the deposition process. The relatively low bulk atomic concentration of carbon in the SiONC thin films (similar to 1%) render these films a possible alternative to SiON, and could become very attractive for the fabrication of integrated optical waveguides, and as a dielectric material in variety of microelectronic and optoelectronic devices. (c) 2006 The Electrochemical Society.