A high efficiency, large area deposition process was developed for silicon oxide films using a scale-up of plasma-enhanced chemical vapor deposition (PECVD) with an additional modified electrode design. We constructed an advanced plasma source by modifying an 8 in. electrode used in small-scale PECVD into a 370 x 470 mm electrode for large area PECVD. The effect of the modified electrode design on the large area and the mechanical properties of the silicon oxide films produced from the setup were examined. Dissociation of octamethylycyclodisiloxane (OMCTS) precursor was controlled by the plasma processing parameters. SiOx films were deposited on polycarbonate substrates by PECVD using OMCTS and oxygen carrier gas. The uniformity of the SiOx film and the mechanical properties were improved by the modified PECVD system design. The plasma was analyzed by optical emission spectroscopy. In addition, we measured the neutral radicals in the plasma by a residual gas analyzer. The mechanical properties of the coatings were examined using a nano-indenter and pencil hardness measurements. The chemical properties of the coatings were examined by Fourier transform infrared spectroscopy. The uniformity and film properties of the SiOx films were controlled by the dissociation of OMCTS using the appropriate intensity of excited neutrals, ionized atoms and input power with RF bias. Crown Copyright (C) 2013 Published by Elsevier B. V. All rights reserved.