Silicon oxynitride (SiOxNy) grown by plasma enhanced chemical vapor deposition (PECVD) is well-suited for the realized application of high contrast waveguides for the range of the refractive index can be largely tuned (1.45-2.0). SiOxNy AWG device with 3% refractive index difference (Δ) and the transmission spectrum of AWG's device indicated the insertion loss, crosstalk and side-lobe were lower than -3 dB, -15 dB and -40 dB, respectively, by 3D beam propagation method were investigated in this study. The chip size of the whole device is smaller than 4 cm x 1.5 cm, and the highest coupling loss of the rib waveguide for single mode fiber was about -1.6 dB. Based on the simulation results, the device can be really fabricated by thin-film deposition, photo-lithography and dry-etching processes.
Microstructural evolution analysis revealed over-supplied silicon atoms would form silicon nano-crystallized structure in the amorphous optical films for lower N2O/(N2+NH3) ratio, and resulted in higher refractive index and extinction coefficient. From the scanning electron microscopy (SEM) features of rib-type silicon oxynitride waveguide, we found the profile, and the roughness of side- and top-walls of waveguide reached to the manufacturing criteria of AWG device. We had successfully fabricated an AWG device with 8 channels and 1.6nm channel spacing, and the coupling loss and propagation loss were about -2.24 dB and -0.15 dB/cm, respectively. While, the AWG device performances need further improvements by modified design, uniform thin film deposition, and accurate dry-etching processes.