Integrated photonic devices with silicon oxycarbide

In this paper, we report on the potential of silicon oxycarbide (SiOC) for integrated photonic applications. SiOC films are developed by reactive radio frequency magnetron sputtering from a silicon carbide (SiC) target in the presence of argon and oxygen gases. The optical properties of the developed SiOC film are characterized with spectroscopic ellispometry over a broad wavelength range 300-1600 nm. The refractive index n of the SiOC film is 2.2 at wavelength lambda = 1550 nm and the extinction coefficient k is estimated to be less than 10(-4) in the near-infrared region above 600 nm. The topography of SiOC films is studied with AFM showing very smooth surface, with rms roughness of 0.24 nm. SiOC film with refractive index n = 2.2 is then patterned by direct laser-writing lithography and etched with reactive ion etching to realize high contrast SiOC core optical waveguides for integrated photonics applications. The waveguide losses are characterized at telecommunication wavelength lambda = 1550 nm. As an example of photonic integrated devices integrating SiOC films, a microring resonator is fabricated where a SiOC layer is used as a coating material for the core of a silicon oxynitride (SiON) waveguide.