Imec's co-integration of its SiN waveguide technology with its active silicon photonics platform

Low propagation loss, accurate phase control, low-loss light coupling, lower thermal variation, and high-power handling are some of the reasons why adding a high-quality silicon nitride (SiN) boosts silicon photonics integrated circuits (PIC). High-quality SiN layers achieving low optical losses and excellent control over the material properties, such as thickness and refractive index variability, are crucial for improving the energy efficiency of Si-based optical transceivers. Since such high-quality SiN layers are deposited by the low-pressure chemical vapour deposition (LPCVD) method at elevated temperatures, it is vital to avoid degrading the performance of the co-integrated baseline Si and Ge devices.

Imec has tackled those integration challenges within its silicon photonics platform ‘iSiPP,’ which is available for industrial partners. Thanks to various engineering updates and changes in the process flow, imec has shown a more than four times reduction of the variability of the resonant wavelength of SiN-based micro-rings compared to the same device made with lower quality PECVD silicon nitride, currently used in the imec platform, without degrading the co-integrated active devices.

Philippe Absil, Vice President at imec: “We are excited to have achieved this major upgrade of our silicon photonics platform. The ability to co-integrate high-quality SiN devices with our baseline technology is important to broaden our offering to our partners who can now consider system simplification with single PIC solutions to combine active and SiN passive functions.”