Silicon photonics has emerged as a critical technology for high-speed data communication, optical interconnects, and integrated photonic circuits. The development of standardized processes and foundry-compatible design kits has been instrumental in advancing the field, enabling researchers and companies to prototype and manufacture photonic integrated circuits (PICs) without requiring in-house fabrication facilities. Industry standards and Process Design Kits (PDKs) play a pivotal role in ensuring design reproducibility, performance predictability, and interoperability across different fabrication platforms.

Foundry PDKs for silicon photonics provide designers with a comprehensive set of rules, models, and component libraries tailored to specific fabrication processes. These PDKs include passive and active photonic components such as waveguides, grating couplers, modulators, and photodetectors, along with their associated electrical interfaces. The PDKs also define design rules for lithography, etching, and doping processes, ensuring compatibility with the foundry’s manufacturing flow. Leading semiconductor foundries, including GlobalFoundries, Tower Semiconductor, and IMEC, offer silicon photonics PDKs that cater to both research and commercial applications.

Multi-project wafer (MPW) services have been a game-changer for silicon photonics, significantly reducing the cost and risk associated with prototyping. MPW runs allow multiple users to share the fabrication cost by combining their designs onto a single wafer. This approach is particularly beneficial for academic institutions, startups, and companies looking to validate their designs before committing to full-scale production. AIM Photonics, a U.S.-based manufacturing institute, has been a key player in providing MPW services for silicon photonics, offering access to advanced fabrication nodes and packaging technologies. Similarly, IMEC in Europe provides MPW runs with state-of-the-art silicon photonics processes, supporting a wide range of applications from telecommunications to biosensing.

Interoperability remains a significant challenge in silicon photonics due to the lack of universal standards for component interfaces and fabrication processes. Different foundries employ varying waveguide geometries, material stacks, and process tolerances, making it difficult to port designs between platforms. For instance, a modulator designed for a 220 nm silicon-on-insulator (SOI) process may not function optimally on a 300 nm SOI platform without substantial redesign. This fragmentation increases development time and costs, particularly for companies seeking to leverage multiple foundries for different aspects of their product lifecycle.

Organizations like AIM Photonics and IMEC are actively working to address these interoperability challenges by promoting standardized process modules and design frameworks. AIM Photonics, for example, has developed a set of process design rules and component libraries that align with industry needs, facilitating smoother transitions between research and production. The institute also emphasizes packaging and testing standards, which are critical for ensuring reliable performance in real-world applications. IMEC, on the other hand, has pioneered advanced integration techniques, such as heterogenous integration of III-V materials on silicon, to expand the functionality of silicon photonics platforms.

Another critical aspect of silicon photonics standardization is the development of compact models for photonic components. These models enable circuit-level simulations and co-design of electronic and photonic elements, which is essential for optimizing system performance. Foundries are increasingly incorporating these models into their PDKs, allowing designers to perform accurate simulations before fabrication. However, discrepancies between simulated and measured performance can still arise due to process variations, underscoring the need for robust statistical modeling and design-for-manufacturing (DFM) methodologies.

The role of industry consortia and partnerships cannot be overstated in driving the adoption of silicon photonics. Collaborative efforts between foundries, research institutions, and end-users help refine PDKs, improve yield, and establish best practices for design and testing. For example, the Silicon Photonics Leadership Group brings together key stakeholders to address technical and economic barriers to widespread adoption. Similarly, the IEEE Photonics Society and other standards bodies are working toward formalizing design and testing protocols to enhance interoperability.

Looking ahead, the evolution of silicon photonics will depend heavily on the continued refinement of PDKs, MPW services, and standardization efforts. Emerging applications in quantum computing, LiDAR, and AI acceleration demand higher levels of integration and performance, pushing the boundaries of existing fabrication processes. Foundries and research institutions must collaborate closely to develop next-generation PDKs that support these advanced applications while maintaining backward compatibility with legacy designs.

In summary, the silicon photonics ecosystem relies on a robust framework of industry standards, foundry PDKs, and MPW services to accelerate innovation and commercialization. While interoperability challenges persist, organizations like AIM Photonics and IMEC are leading the charge in establishing unified design and manufacturing practices. As the technology matures, further standardization and collaboration will be essential to unlock the full potential of silicon photonics in a wide range of applications.