Low Hydrogen Component SiN Films by PECVD for Low Propagation Loss Waveguide

Hydrogen component in SiN films synthesized using plasma enhanced chemical vapor deposition at low temperature (350°C) using silane and nitrogen was studied by Fourier transform infrared spectrum. The effects of the SiH
4
/N
2
flow ratio and the radio frequency power on the hydrogen components of SiN films were investigated. Some sub-micron (400nm×700nm) waveguides were fabricated using corresponding optimal SiN films. The propagation loss is found to be as less as ~-2.12dB/cm at 1550nm. The whole waveguide fabrication of process was at low temperature. It is indicated that low hydrogen SiN waveguide preparation method is a promising method in photonics integrated circuits for new generation communications applications.