Integrated optical devices with silicon oxynitride prepared by plasma-enhanced chemical vapor deposition (PECVD) on Si and GaAs substrates

Plasma-enhanced chemical-vapor deposition (PECVD) is demonstrated as a technique for manufacturing silicon oxynitride thin films that permit the deposition of integrated optical components on Si and III/V-semiconductors. PECVD process parameters are optimized for a conventional parallel plate reactor using silane, nitrogen, and oxygen to yield homogeneous thicknesses and refractive indices across the wafer. The waveguide types utilized for the study are strip-loaded and trench-bulge waveguides, and the SiO(x)N(y) characteristics resulting from the optimized PECVD process include homogeneity and reproducibility. Optical components can be fashioned in this manner to produce directional couplers, dielectric mirrors, fiber coupling, and integrated detectors. The trench-bulge waveguides are found to provide the advantages of zero crosstalk to neighboring waveguides, scratch protection, and improved lateral confinement.