University of Sydney develops ‘Lego-like’ electro-optical chip architecture

04 Dec 2023

Integrating electronics with photonics has applications in satellites, wireless, and 6G telecoms.

Flexible chip: integration of As2S3 waveguides and silicon components. Click for info.

Researchers at the University of Sydney Nano Institute have invented a compact silicon semiconductor chip that integrates electronics with photonic components. The new technology significantly expands radio-frequency bandwidth and the ability to accurately control information flowing through the unit.

Expanded bandwidth means more information can flow through the chip and the inclusion of photonics allows for advanced filter controls, creating a versatile new semiconductor device.

Researchers expect the chip will have application in advanced radar, satellite systems, wireless networks and the roll-out of 6G and 7G telecommunications and also open the door to advanced sovereign manufacturing. It could also assist in the creation of high-tech value-add factories at places like Western Sydney’s Aerotropolis precinct.

The chip is built using an emerging technology in silicon photonics that allows integration of diverse systems on semiconductors less than 5 millimetres wide. Pro-Vice-Chancellor (Research) Professor Ben Eggleton, who guides the research team, likened it to fitting together Lego building blocks, where new materials are integrated through advanced packaging of components, using electronic chiplets.

The research for this invention has been published in Nature Communications.

Australian potential

Dr Alvaro Casas Bedoya, Associate Director for Photonic Integration in the School of Physics, who led the chip design, said the unique method of heterogenous materials integration has been 10 years in the making.

“The combined use of overseas semiconductor foundries to make the basic chip wafer with local research infrastructure and manufacturing has been vital in developing this photonic integrated circuit,” he said. “This architecture means Australia could develop its own sovereign chip manufacturing without exclusively relying on international foundries for the value-add process.”

Prof. Eggleton highlighted the fact that most of the items on the Australian Government’s List of Critical Technologies in the National Interest depend upon semiconductors. He said the invention means the work at Sydney Nano fits well with initiatives like the [Australian] Semiconductor Sector Service Bureau (S3B), sponsored by the New South Wales Government, which aims to develop the local semiconductor ecosystem.

Dr Nadia Court, Director of S3B, commented, “This work aligns with our mission to drive advancements in semiconductor technology, holding great promise for the future of semiconductor innovation in Australia. The result reinforces local strength in research and design at a pivotal time of increased global focus and investment in the sector.”

Designed in collaboration with scientists at the Australian National University, the integrated circuit was built at the Core Research Facility cleanroom at the University of Sydney Nanoscience Hub, a purpose-built A$150 million (US$100 million / €92 million) building with advanced lithography and deposition facilities.

The photonic circuit in the chip means a device with a 15 gigahertz bandwidth of tunable frequencies with spectral resolution down to just 37 MHz, which is less than a quarter of one percent of the total bandwidth. Professor Eggleton said, “Led by our PhD student Matthew Garrett, this invention is a significant advance for microwave photonics and integrated photonics research.

“Microwave photonic filters play a crucial role in modern communication and radar applications, offering the flexibility to precisely filter different frequencies, reducing electromagnetic interference and enhancing signal quality. Our innovative approach of integrating advanced functionalities into semiconductor chips, particularly the heterogenous integration of chalcogenide glass with silicon, holds the potential to reshape the local semiconductor landscape.”

Co-author and Senior Research Fellow Dr Moritz Merklein said, “This work paves the way for a new generation of compact, high-resolution RF photonic filters with wideband frequency tunability, particularly beneficial in air and spaceborne RF communication payloads, opening possibilities for enhanced communications and sensing capabilities.”