HSINCHU, Taiwan, December 8, 2025 — United Microelectronics Corporation (NYSE: UMC; TWSE: 2303)(“UMC”), a leading global semiconductor foundry, today announced a licensing agreement with imec, a world-leading research and innovation hub in advanced semiconductor technologies, for the transfer of imec’s iSiPP300 silicon photonics process, featuring co-packaged optics (CPO) compatibility, to accelerate UMC’s silicon photonics roadmap. The licensed technology will enable UMC to bring a 12-inch silicon photonics platform to market targeting next-generation connectivity.

With copper interconnects facing limitations amid growing AI data workloads, silicon photonics – using light to transmit data - is developing rapidly to support the ultra-high bandwidth, low latency, and energy-efficient requirements for data centers, high performance computing, and networking infrastructure. Tapping into this high-growth market, UMC will integrate imec’s proven 12-inch silicon photonics process technology with its own expertise in silicon-on-insulator (SOI) wafer processing and leverage prior experience in 8-inch silicon photonics production to provide customers with a highly scalable photonic IC (PIC) platform.

GC Hung, UMC Senior Vice President, said: “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 well 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, energy-efficient, and highly scalable optical interconnects for both intra- and inter-data center communications.”

Philippe Absil, Vice-President of IC-Link by imec, said: “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 very 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.”

About UMC

UMC (NYSE: UMC, TWSE: 2303) is a leading global semiconductor foundry company. The company provides high-quality IC fabrication services, focusing on logic and various specialty technologies to serve all major sectors of the electronics industry. UMC’s comprehensive IC processing technologies and manufacturing solutions include Logic/Mixed-Signal, embedded High-Voltage, embedded Non-Volatile-Memory, RFSOI, BCD etc. Most of UMC's 12-in and 8-in fabs with its core R&D are located in Taiwan, with additional ones throughout Asia. UMC has a total of 12 fabs in production with combined capacity of more than 400,000 wafers per month (12-in equivalent), and all of them are certified with IATF 16949 automotive quality standard. UMC is headquartered in Hsinchu, Taiwan, plus local offices in United States, Europe, China, Japan, Korea & Singapore, with a worldwide total of 20,000 employees. For more information, please visit: http://www.umc.com.

Note from UMC Concerning Forward-Looking Statements

Some of the statements in the foregoing announcement are forward-looking within the meaning of the U.S. Federal Securities laws, including statements about introduction of new services and technologies, future outsourcing, competition, wafer capacity, business relationships and market conditions. Investors are cautioned that actual events and results could differ materially from these statements as a result of a variety of factors, including conditions in the overall semiconductor market and economy; acceptance and demand for products from UMC; and technological and development risks. Further information regarding these and other risks is included in UMC’s filings with the U.S. Securities and Exchange Commission. UMC does not undertake any obligation to update any forward-looking statement as a result of new information, future events or otherwise, except as required under applicable law.