Low-Temperature and Low-Pressure Silicon Nitride Deposition by ECR-PECVD for Optical Waveguides

We report on low-temperature and low-pressure deposition conditions of 140 °C 1.5 mTorr, respectively, to achieve high-optical quality silicon nitride thin films. deposit the films using an electron cyclotron resonance plasma-enhanced chemical vapour (ECR-PECVD) chamber with Ar-diluted SiH4, N2 gas. Variable-angle spectroscopic ellipsometry was used determine thickness refractive index films, which ranged from 300 650 nm 1.8 2.1 at 638 nm, respectively. Rutherford backscattering spectrometry composition including oxygen contamination, elastic recoil detection characterize removal hydrogen after annealing. The as-deposited are found have variable relative nitrogen compositions significant content incorporation 10–20 17–21%, Atomic force microscopy measurements show a decrease in root mean square roughness annealing for variety Prism coupling losses as low 1.3, 0.3 ± 0.1 dB/cm 638, 980 1550 without need post-process Based this study, we find that ECR-PECVD SiOxNy:Hz suitable thickness, optical loss their use visible near-infrared integrated photonic devices.