News: Optoelectronics
1 February 2023
Imec co-integrates SiN waveguide technology with active silicon photonics platform
In an invited talk at SPIE Photonics West 2023 in San Francisco, CA, USA (28 January to 2 February), nanoelectronics research center imec of Leuven, Belgium announced that it has demonstrated the co-integration of its silicon nitride waveguide technology with its silicon photonics platform — without any degradation in performance of the high-bandwidth active devices. An important upgrade for imec’s silicon photonics platform, the result enables the synthesis of high-quality wavelength-selective devices and other optical passive functions that benefit from accurate optical phase control, meeting market demands for optical transceivers for datacom, light detection & ranging (LiDAR) and other applications.
Low propagation loss, accurate phase control, low-loss light coupling, lower thermal variation, and high power handling are some of the reasons why adding 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 silicon-based optical transceivers. Since such high-quality SiN layers are deposited by low-pressure chemical vapor deposition (LPCVD) at elevated temperatures, it is vital to avoid degrading the performance of the co-integrated baseline silicon and germanium devices.
Imec has tackled those integration challenges within its iSiPP silicon photonics platform, which is available for industrial partners. Due to various engineering updates and changes in the process flow, imec has, for example, shown a more than four times reduction in the variability of the resonant wavelength of SiN-based micro-rings compared with the same device made with lower-quality PECVD silicon nitride currently used in the imec platform, without degrading the co-integrated active devices.
“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,” says Philippe Absil, vice president at imec.
