We report that the dielectric constant of hydrogenated carbon nitride (HCNx) film is 1.88 +/- 0.06 at 1 kHz at room temperature. The film was deposited on p-Si (100) wafer by CH4/N-2 (1: 4) atmospheric pressure dielectric barrier discharge (DBD) plasma. The dielectric constant of HCNx film decreases from 1.88 to 1.71 (+/- 0.06) as the applied frequency increases from 1 kHz to 5 MHz. Round shaped island growth has been observed at film surface area in scanning electron microscopy (SEM). The chemical compositions were investigated by means of X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX) and elemental analysis. (C) 2011 Elsevier B. V. All rights reserved.