Silicon-rich silicon nitride CMOS compatible photonics (Conference Presentation)

Silicon photonic technologies have undoubtedly revolutionized the optical communication and photonic industries during the last 10 years. Silicon on insulator (SOI) devices are now routinely used to build high performance transceivers and optical components, with a privileged route to the integration with electronic devices. However, in order to increase the density of integration and demonstrate advanced functionality, other materials showing complementary characteristics to those exhibited by silicon are needed. In this context, we recently developeds a tuneable index back end of line (BEOL)-compatible platform, based on silicon nitride, in which the content of silicon can be selectively varied to tailor the optical characteristics of the material. This granted the ability to change the material transparency window and its linear and nonlinear optical response in various wavelength regions. This advanced platform allowed us to demonstrate various photonic devices, exhibiting extremely low loss and capable of performing functionality that are not allowed in silicon. Moreover, the developed platform is fully CMOS and BEOL compatible and only low temperature processes (<350 °C) are utilized during the fabrication steps. In this work we describe the CMOS fabrication protocols developed for this platform as well as various recently realized applications/devices, such as MUX/DEMUX in the O-band, advanced nonlinear devices and novel photonic components operating in the 2 µm window