Electron cyclotron resonance plasma enhanced chemical vapor deposition of hydrogen-free SiCN films has been studied. Infrared and Raman spectroscopies were used for chemical characterization of deposited films, showing Si-N, Si-C, Si-Si, and C-N bonds in composition. Optical responses of the films between 1.5 and 4.5 eV were obtained by spectroscopic ellipsometry. Cathodoluminescence of the films shows mainly a broad band of emission at around 2.3 eV together with overlapped contributions at higher energies depending on the composition. Surface morphology and roughness has been investigated by atomic force microscopy. (c) 2007 The Electrochemical Society.