Characteristics of Silica-on-Silicon Platform with Silicon Oxide Treatment for Hybrid Integrated Optical Module

To investigate the effects of the silicon oxide process on the characteristics of the silica planar lightwave circuit (PLC) platform, we have compared two silicon oxide formation processes, thermal oxidation and plasma-enhanced chemical vapor deposition (PECVD). The thermal oxidation process for forming a silicon oxide layer on the silica platform generates surface defects and a crystobalite crystal phase, resulting in the deterioration of optical waveguide characteristics. However, the silica platform with a silicon oxide layer formed by PECVD has a transparent planar optical waveguide by suppressing the crystal growth of silica due to low processing temperatures.