c g of

2 an (PECVD). Layer properties such as refractive index, deposition rate, thickness non-uniformity and hydrogen bond content were correlated to the based dielectrics such as silicon oxynitride (SiOxNy:H or ammonia (NH3). In the present study a relation is established between the layer properties and the deposition process reproducibility of the refractive index and the thickness of the telecom applications [2,4,5,8–10]. In this work, we focus on the correlation between the deposition parameters and the PECVD SiOxNy:H layer properties, in order to identify those trends which lead to Thin Solid Films 515 (2007parameters. We will restrict ourselves to high frequencyshortly SiON) as a promising material for densely integrated optics [1–5]. This is mainly due to the possibility of obtaining high refractive index (n) contrast waveguiding structures for a broad wavelength range from visible to IR by changing the nitrogen/oxygen composition from SiO2 (n=1.46) to Si3N4 (n=2.0). In practice preferentially use is made of plasma-enhanced chemical vapor deposition (PECVD) as it allows for relatively high deposition rates at low temperatures (b400 °C). The PECVD SiOxNy:H layers are mostly grown from nitrous oxide (N2O) and silane (SiH4/N2) with optional an addition of layers are highly important parameters. The structural and optical properties, like the index and loss, of the PECVD SiOxNy:H layers are strongly dependent on the layer compo-sition [7]. This, in turn can be controlled by the parameters of the PECVD process, like the flow rate and the ratio of the process gases, the chamber pressure, the radio frequency (RF) power and the substrate temperature. A serious drawback of the chosen deposition process is the incorporation of undesirable N–H and Si–H bonds in the layers [2,4–6], which significantly increase the optical loss in the spectral region of interest forwere characterized by spectroscopic ellipsometry, X-ray Photoelectron Spectroscopy, Fourier Transform Infrared spectroscopy and prism coupler techniques. A simple atomic valence model is found to describe the measured atomic concentrations for PECVD silicon oxynitride layers