UMC signs imec silicon photonics deal for 12-inch wafers

UMC has signed a licensing agreement with imec for silicon photonics process technology, giving it access to imec's iSiPP300 platform for 12-inch wafers.

The agreement focuses on transferring imec's silicon photonics process to UMC as the foundry expands its work in optical interconnect technology. The licensed platform is compatible with co-packaged optics, a design approach that places optical and compute elements closer together to improve data movement inside advanced systems.

Silicon photonics is drawing greater attention across the semiconductor sector as data centre and artificial intelligence workloads put growing pressure on conventional copper interconnects. The technology uses light rather than electrical signals to transmit data, and chipmakers see it as one way to meet higher bandwidth demand and lower latency requirements in networking and computing systems.

Under the arrangement, UMC plans to combine imec's 12-inch silicon photonics process with its own silicon-on-insulator wafer manufacturing experience. It also pointed to earlier work in 8-inch silicon photonics production as a foundation for developing a larger-wafer photonic integrated circuit platform for customers.

The move places UMC in a market several semiconductor groups are targeting as optical links become more important in data centres, high-performance computing and network infrastructure. Using 12-inch wafers can offer economies of scale over smaller formats, one reason foundries and customers have been working to move silicon photonics onto more mainstream manufacturing lines.

Customer plans

GC Hung outlined how UMC expects to use the technology. "We are pleased to license state-of-the-art silicon photonics process technology from imec, which will enable UMC to accelerate the readiness of our photonic platform on 12-inch wafers. UMC is working with several new customers to deliver PIC chips on this new platform for optical transceiver applications, with risk production slated for 2026 and 2027. Furthermore, combined with our diverse advanced packaging technologies, UMC is positioned to extend our offerings going forward as system architectures evolve toward greater integration, such as co-packaged optics and optical I/O, to achieve high-bandwidth and highly scalable optical interconnects for both intra- and inter-data center communications," said Hung, Senior Vice President, UMC.

The reference to customers suggests UMC is already in discussions with users of optical transceivers, key components in links between servers, switches and storage systems. It also points to a broader strategy combining wafer manufacturing with packaging as semiconductor companies try to serve customers building more tightly integrated systems.

Co-packaged optics has become a closely watched area because it aims to reduce the bottlenecks and power demands that can arise when data moves between processors and network equipment. Optical I/O, another area UMC mentioned, is also under study across the industry as designers look for alternatives to electrical interconnects in systems that must handle larger AI model training and inference workloads.

Imec platform

Imec said its iSiPP300 platform has been developed over several years on 12-inch wafers using advanced CMOS processing. The research group said the technology includes microring-based filters and modulators, GeSi electro-absorption modulators, low-loss fibre interfaces and 3D packaging modules.

Philippe Absil set out imec's view of the platform's manufacturing potential. "Over the past decade, imec has shown that advanced CMOS processing on 12-inch wafers for silicon photonics can deliver significant performance gains. Our iSiPP300 platform features compact and energy-efficient devices, including microring-based filters and modulators, as well as GeSi electro-absorption modulators (EAMs), complemented with diverse low-loss fiber interfaces and 3D packaging modules. IC-Link by imec works closely with the semiconductor industry to ensure that the most advanced technologies are available for product manufacturing, and this agreement with UMC is a demonstration of our collaborative approach, enabling us to bring cutting-edge silicon photonics solutions to a broader market and accelerate adoption in next-generation compute systems," said Absil, Vice-President of IC-Link, imec.

The technology transfer reflects a familiar model in the chip industry, in which research institutes develop manufacturing building blocks and foundries adapt them for commercial production. For UMC, the agreement adds another option in specialty manufacturing at a time when foundries are looking beyond standard logic processes to differentiate themselves in areas tied to communications, automotive and industrial demand.

UMC is one of the larger contract chipmakers, with 12 fabrication plants in production and combined monthly capacity of more than 400,000 wafers on a 12-inch-equivalent basis. Its manufacturing base is concentrated in Taiwan, where most of its 12-inch and 8-inch plants and core research and development operations are located.

The company employs about 20,000 people worldwide and provides fabrication services across logic, mixed-signal and several specialty process technologies. The addition of a 12-inch silicon photonics platform suggests optical interconnects are moving further into the mainstream priorities of established foundries as data infrastructure requirements continue to shift.