https://cdn.specpick.com/images/photonics/imechybrdfinfet_wall.jpg712370
imec has demonstrated ultra-low power, high-bandwidth optical transceivers through hybrid integration of Silicon Photonics and FinFET CMOS technologies. With a dynamic power consumption of only 230fJ/bit and a footprint of just 0.025mm2, the 40Gb/s non-return-to-zero optical transceivers mark an important milestone in realizing ultra-dense, multi-Tb/s optical I/O solutions for next-generation high-performance computing applications.
The exponentially growing demand for I/O bandwidth in datacenter switches and high-performance computing nodes is driving the need for tight co-integration of optical interconnects with advanced CMOS logic, covering a wide range of interconnect distances (1m-500m+). In the presented work, a differential FinFET driver was co-designed with a Silicon Photonics ring modulator, and achieved 40 Gb/s NRZ optical modulation at 154 fJ/bit dynamic power consumption.
The receiver included a FinFET trans-impedance amplifier (TIA) optimized for operation with a Ge waveguide photodiode, enabling 40Gb/s NRZ photodetection with an estimated sensitivity of -10 dBm at 75 fJ/bit power consumption. High-quality data transmission and reception was also demonstrated in a loop-back experiment at 1330nm wavelength over standard single mode fiber (SMF) with 2dB link margin. Finally, a 4 x 40 GB/s, 0.1 mm2 wavelength-division multiplexing (WDM) transmitter with integrated thermal control was demonstrated, enabling bandwidth scaling beyond 100 Gb/s per fiber.
According to Joris Van Campenhout, director of the Optical I/O R&D program at imec, the demonstrated hybrid FinFET-Silicon Photonics platform integrates high-performance 14 nm FinFET CMOS circuits with imec’s 300 mm Silicon Photonics technology through dense, low-capacitance Cu micro-bumps. Careful co-design in this combined platform has enabled to demonstrate 40 Gb/s NRZ optical transceivers with extremely low power consumption and high bandwidth density. Through design optimizations, they expect to further improve the single-channel data rates to 56 Gb/s NRZ. Combined with wavelength-division multiplexing, these transceivers provide a scaling path to ultra-compact, multi-Tb/s optical interconnects, which are essential for next-generation high-performance systems.
This work was carried out as part of imec’s industrial affiliation R&D program on Optical I/O and was presented at the 2018 Symposia on VLSI Technology and Circuits (June 2018). Imec’s 200 mm and 300 mm Silicon Photonics technologies are available for evaluation by companies and academia through imec’s prototyping service and the iSiPP50G multi-project wafer (MPW) service.