This collaboration signals the transition of optical networking from the "front panel" (pluggable transceivers) to the "heart of the chip." By using microLEDs and 3D stacking, the partners are building a high-speed optical fabric directly inside the processor architecture to bypass the thermal and power bottlenecks of copper.
The challenge: The "copper wall" in AI
As AI models grow, the traditional copper traces on circuit boards are struggling to move data fast enough without generating excessive heat. CEA-Leti, a world-leading micro and nanotechnologies research institute, and CEA-List, a specialist in smart digital systems, have announced a strategic collaboration with Powerchip Semiconductor Manufacturing Corporation (PSMC) to solve this using light.
The partnership will integrate high-bandwidth optical communication directly into PSMC's 3D stacking and interposer platforms. This addresses the physical limits of copper interconnects, increasingly stringent power budgets, and the need for scalable computing.
The solution: Integrating RISC-V and microLEDs
The project focuses on integrating short-reach, high-bandwidth optical links with customisable RISC-V processor architectures.
RISC-V for flexibility: Olivier Thomas, deputy head of the digital IC design division at CEA-List, explains that RISC-V’s open architecture allows for compute platforms tailored specifically to performance and power targets.
MicroLEDs for efficiency: Sébastien Dauvé, CEO of CEA-Leti, notes that microLED technology is the engine for this throughput. "MicroLED will boost optical-communication throughput using low-power GaN [Gallium Nitride] LED solutions," he says.
The industrial impact: Foundry-ready AI chiplets
The inclusion of PSMC, a major global semiconductor foundry, is critical. It moves this technology from a research concept to a manufacturable service.
Dr Shou-Zen Chang, CTO of PSMC, confirms the foundry will provide services for next-generation AI applications by combining CEA-Leti and CEA-List's IP with PSMC’s 3D stacking technology. This essentially creates a "foundry ecosystem" for optical chiplets.
