SiOC films made by the inductive coupled plasma chemical vapor deposition were analyzed by the photo luminance spectra and reflectance. Chemical shift obtained by PL spectra was observed and the reflectance was decreased at sample with low refractive index. The refractive index was in inverse proportion to the thickness of SiOC film. Lowering the reflectance caused to decrease the energy band gap and polarization, so increased an absorbance of the light. Low polarization of SiOC film was induced from the recombination and dissociation of alkyl sites by neighboring high electro negative oxygen. The electron affinity related to the energy band gap at surfaces increased at sample with low polarization, and finally, the reflectance decreased according to the reduction of polarity. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.