Low-temperature deposition of high-quality silicon oxynitride films for CMOS-integrated optics

The growth of silicon oxynitride thin films applying remote inductively coupled, plasma-enhanced chemical vapor deposition is optimized toward high optical quality at a deposition temperature as low as 150°C. Propagation losses of 0.5±0.05 dB/cm, 1.6±0.2 dB/cm, and 0.6±0.06 dB/cm are measured on as-deposited waveguides for wavelengths of 1300, 1550, and 1600 nm, respectively. Films were deposited onto a 0.25 μm technology mixed-signal CMOS chip to show the application perspective for three-dimensional integrated optoelectronic chips.