Fraunhofer IPMS achieves milestone in quasi-monolithic Chip Integration

As part of the SpectroNet network, we are pleased to share exciting news from our member Fraunhofer Institute for Photonic Microsystems IPMS, which has achieved an important milestone in the European APECS pilot line for advanced semiconductor packaging and heterogeneous integration.

Researchers at Fraunhofer IPMS have successfully demonstrated a key step toward quasi-monolithic integration (QMI) — a promising approach that enables different chip components to be combined almost seamlessly into one compact system. By embedding small chiplets into specially structured silicon pockets at the wafer level, Fraunhofer IPMS is helping to bridge the gap between traditional chip packaging and next-generation semiconductor manufacturing.

The growing demand for higher computing power, greater system complexity, and more compact electronic systems requires new approaches in microelectronics. Future systems must combine the performance and compactness of a single chip with the flexibility of modular building blocks. This is precisely where QMI offers a highly promising solution.

Within the APECS pilot line, which focuses on Advanced Packaging and Heterogeneous Integration for Electronic Components and Systems, Fraunhofer IPMS is developing technologies that allow components such as control electronics, sensors, and MEMS to be integrated at wafer level. The current demonstrator marks the first critical milestone on the QMI roadmap.

The basis of the technology is a silicon wafer with structured recesses, known as pockets. For the first time, dummy chiplets have been placed into these pocket wafers and the surface has been levelled with a passivation layer to prepare for subsequent back-end-of-line wiring. This creates a nearly monolithic system architecture that combines very high integration density with modular scalability.

Compared to conventional packaging processes, QMI offers several important advantages. Shorter signal paths can reduce losses and latency, thereby improving system performance. Fewer mechanical interfaces can increase reliability and system lifetime. At the same time, the nearly monolithic integration of components saves valuable space and supports cost-efficient, scalable manufacturing.

These benefits make quasi-monolithic integration highly relevant for future applications such as highly integrated system-on-chip solutions for artificial intelligence, smart transceivers with high bandwidth, and advanced heterogeneous system architectures.

Although the current demonstrator is based on dummy structures, Fraunhofer IPMS emphasizes that the process chain can be transferred to real-world customer applications. This opens up new opportunities for industrial partners whose products depend on the integration of different high-density technologies.

The work is being carried out as part of the European APECS pilot line, which receives funding from the Chips Joint Undertaking and national grants from several European countries under the Chips for Europe initiative. With total funding of €730 million over four and a half years, APECS represents a major European effort to strengthen innovation and production capabilities in advanced microelectronics.

For the SpectroNet community, this achievement is a strong example of how applied research, photonic microsystems, semiconductor technologies, and industrial collaboration can drive the next generation of high-performance integrated systems.

We congratulate Fraunhofer IPMS on this important milestone and look forward to following the further development of quasi-monolithic integration toward industrial deployment.

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