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The simulation, fabrication and characterization of ARROW waveguides using dielectric films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) and Sputtering techniques, are presented in this work. Amorphous titanium oxide (TiO2) films were used as first cladding layer and silicon oxynitride (SiOxNy) films, as core layer. Furthermore, homemade routines based in two computational methods were used, for numerical simulations: Transfer Matrix Method (TMM) for the determination of the optimum thickness values of the Fabry-Perot layers, and the Finite Difference Method (FDM) for 2D design and determination of the maximum width that allows single-mode operation. The utilization of thermally grown silicon oxide as second anti-resonant layer, along with improvements in the Reactive Ion Etching conditions for the definition of sidewalls of the optical waveguides were responsible for diminishing optical attenuations. Optimization of the waveguide rib height was done both through FDM simulations and experimentally. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A set of MOS capacitors with TiOxNy films as gate dielectric layer was fabricated and characterized. The TiOxNy films were deposited by reactive r.f. magnetron sputtering varying the nitrogen and oxygen partial pressure in a Ar/N2/O2 gaseous mixture. The TiOxNy films were characterized by, Rutherford Backscattering (RBS), X-ray absorption near edge spectroscopy (XANES) in oxygen K-edge (O-K), optical absorption and High Resolution Transmission Electron Microscopy (HRTEM). Capacitance-voltage (1MHz) and current-voltage measurements were performed to obtain the effective dielectric constant, the effective oxide thickness (EOT), the leakage current density, and the interface quality. MOS capacitors results show that the TiOxNyfilms dielectric constant varies from 28 to 80, present a good interface quality with silicon, and the leakage current density values are in the order of 0.25 mA/cm2 for VG = –2V, which is acceptable for high performance logic circuits and low power circuits fabrication. The leakage current density is reduced in 2 orders of magnitude for increasing nitrogen concentration (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

ARROW waveguides with sputtered-TiOxNy anti-resonant 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. TiOxNy 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. (© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)