Silicon oxynitrides with compositions varying from
Si3 N4 to SiO2 were deposited on silicon substrates by electron cyclotron resonance plasma enhanced chemical vapour deposition (ECRPECVD). The silicon source used is an organic liquid, Tris Dimethyl Amino Silane (trade name SiN– 1000TM). Optical emission spectroscopy is used to characterize the ECR plasma, this information then is correlated with the optical properties of the deposited film, as determined by in situ ellipsometry. Auger electron spectroscopy showed that only low levels of carbon (< 3 at%) are present. The SiO2 and Si3 N4 films are close to stoichiometric, with low levels of bonded hydrogen as determined by infrared absorption spectroscopy.
Planar waveguide structures were fabricated and tested using the prism coupling technique to determine the mode effective indices. These are compared to those expected from the ellipsometry measurements.