11 Jul 2018
Hybrid integration of FinFET logic and silicon photonics modulator creates tiny, ultra-low-power devices for high-speed optical interconnects.
A team at the Belgian microelectronics research center imec claims to have demonstrated extremely compact and efficient optical transceivers with a combination of advanced logic and silicon photonics devices.
The engineers say that their work, initially presented last month in Hawaii at the 2018 Symposia on VLSI Technology and Circuits event, marks a "milestone" in the development of optical interconnects for use in future high-performance computing systems.
To reach that milestone, they combined so-called “FinFET” logic devices - extremely fast field-effect transistors based on a three-dimensional architecture - with a silicon photonics process on a full-size (300 mm diameter) silicon wafer and 1330 nm laser diode emitter.
The resulting 40 Gb/s transceivers, covering an area of just 0.025 mm2, also offer ultra-low power consumption and are therefore seen as highly suited to deployment in data centers – where power consumption is a key consideration and cost for operators.
“With a dynamic power consumption of only 230 fJ/bit and a footprint of just 0.025 mm2, the 40Gb/s non-return-to-zero (NRZ) optical transceivers mark an important milestone in realizing ultra-dense, multi-Tb/s optical I/O solutions for next-generation high-performance computing applications,” remarked imec.
As well as the basic device concept, the team demonstrated data transmission and reception over a singlemode fiber, and built a 4 x 40 Gb/s wavelength-division multiplexing (WDM) transmitter – showing that bandwidths of beyond 100 Gb/s per fiber are possible with the design.
Joris Van Campenhout, director of imec’s optical I/O research and development program, said in a release from the Leuven group: “The demonstrated platform integrates high-performance 14 nm FinFET CMOS circuits with imec’s 300 mm silicon photonics technology through dense, low-capacitance copper micro-bumps.
“Careful co-design in this combined platform has enabled us to demonstrate 40 Gb/s NRZ optical transceivers with extremely low power consumption and high bandwidth density.
“Through design optimizations, we 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.”
• For more details of imec’s development of silicon photonics technology, visit the research center’s dedicated web pages.