ARROW waveguides with sputtered-TiOxNy antiresonant layers obtained with different nitrogen concentration in the gaseous mixture were fabricated and characterized. A study of the influence of this parameter on the losses of the waveguides is presented in this work. TiOxN y films have very high refractive indexes, which is a very important characteristic for the first ARROW layer, since this layer behaves like a Fabry-Perot resonator in anti-resonance. Optical and compositional properties of the TiOxNy films were also studied and the results are presented. These films were characterized by Rutherford Backscattering Spectroscopy (RBS), FTIRs, optical absorption and ellipsometry. The second anti-resonant layer and the core of the waveguides were composed of thermally grown SiO2 and PECVD-SiOxNy, respectively. Optical characterization results show propagation losses as low as 1.18 dB/cm for single-mode waveguides fabricated with TiOxNy films obtained with 25% of nitrogen in the gaseous mixture. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.