We have synthesized a material, boron oxynitride (BON), deposited as films on Si(100) substrates by low frequency rf-derived plasma-assisted metalorganic chemical vapor deposition (MOCVD), and have studied the electrical and optical properties of these films. The effects of growth conditions such as the flux of the feed gas and growth time on these properties are investigated. Our data show that the electrical resistance decreases with an increase in nitrogen flux and growth time. Amorphous BON thin films grown at relatively low temperatures have higher resistance than microcrystal-containing films deposited at high temperature. Thus by controlling the nitrogen content of the film we can make BON thin films that are either semiconducting or insulating. We also monitored optical emission spectra (OES) during MOMCVD to analyze reaction of the gas phase in the plasma. Based on the OES result we confirm that BON thin films can be prepared under a nitrogen plasma. (C) 2003 American Vacuum Society.