An innovative kinetic model allowing insight in the moderate temperature chemical vapor deposition of silicon oxynitride films from tris(dimethylsilyl)amine

Abstract

An apparent kinetic model is developed for a novel chemical vapor deposition (CVD) process of silicon oxynitride (SiOxNy) films from tris(dimethylsilyl)amine (TDMSA) and O2, operating at moderate temperature (600–650 °C) and at atmospheric pressure. The definition of reaction pathways and the extraction of kinetic information is based on recently reported results of the gas phase composition, complemented by solid phase characteristics obtained by spectroscopic ellipsometry (SE) and ion beam analyses (IBA). Incorporation of carbon (up to 20 at.%) is considered alongside nitrogen (up to 25 at.%) for variable O2 flow rates (0.3–1.2 sccm). This combined gas- and solid-phase analysis is utilized to identify the main gaseous species and provide insight into the deposition mechanism. A silicon- and a nitrogen-centered radical intermediates are considered as the primary species of the mechanism, based on evidence from gas phase characterizations. A third, fictitious, nitrogen- and carbon-containing molecule is also conceptualized to account for carbon incorporation. Eight chemical reactions are defined alongside their respective kinetic parameters and are implemented in the ANSYS® FLUENT® computational fluid dynamics (CFD) code. Upon validation, the model allows for the successful prediction of local deposition rates and SiOxNy film composition containing non-negligible carbon, marking it as the first kinetic model able to represent the main chemical mechanisms involved in the CVD of a four-component material. The reported combined approach could be applied to other existing or new CVD chemistries forming multi-component thin films, favoring their implementation in original applications.