Fraunhofer Gesellschaft zur Förderung der angewandten Forschung

Fraunhofer is Europe’s largest application-oriented research organization. Our research efforts are geared entirely to people’s needs: health, security, communication, energy and the environment. As a result, the work undertaken by Fraunhofer researchers and developers has a significant impact on people’s lives. Its services are solicited by customers and contractual partners in industry and public administration.

Company profile

The Fraunhofer-Gesellschaft based in Germany is the world’s leading applied research organization. Prioritizing key future-relevant technologies and commercializing its findings in business and industry, it plays a major role in the innovation process. A trailblazer and trendsetter in innovative developments and research excellence, it is helping shape our society and our future. Founded in 1949, the Fraunhofer-Gesellschaft currently operates 76 institutes and research units throughout Germany. Over 30,000 employees, predominantly scientists and engineers, work with an annual research budget of €2.9 billion. Fraunhofer generates €2.5 billion of this from contract research.

The Fraunhofer Institute for Microstructure of Materials and Systems (IMWS) primarily focusses on research in microstructure diagnostics and microstructure-based process design. Over the last 25 years, our researchers have gained experience particularly in the development and application of high-resolution defect localization and failure diagnostic methods. In close cooperation with manufacturers of electronic devices along the supply chain, these methods were applied for process characterization, physical failure analysis, micromechanical testing and simulation in the fields of IC- and power electronic device manufacturing, sensor development and advanced packaging technologies. The Fraunhofer IMWS is internationally recognized for its expertise in failure diagnostics on GaN devices to identify process induced defects and explore related failure modes and degradation mechanisms during operation.

The Fraunhofer IAF develop electronic and optoelectronic devices, based on III-V semiconductors, for a wide range of applications. As one of the leading research facilities worldwide in the area of III-V semiconductors, we cover the entire value chain: our core competences range from materials research, design, technology and circuits to modules and systems. High frequency circuits for communication technology, robust gallium nitride voltage converters for efficient use of regenerative energies, infrared and UV detectors, semiconductor lasers for the detection of hazardous substances, micro-sensors for gas and fluid analysis, or innovative diamond technologies – this is only a small selection of developments with which the Fraunhofer IAF advances research and the development of innovative semiconductor technologies.

The Fraunhofer IZM is conducting applied research in the area of microelectronic packaging, which is a key technology for every electronic application. It connects the individual components to a microsystem, protects it against vibration and moisture and dissipates heat reliably. In short, it ensures that electronics continue to function reliably in even the harshest conditions. Clever packaging also reduces the manufacturing costs for complex electronic systems. With its application-oriented research, Fraunhofer IZM bridges the gap between microelectronic component providers and technical system manufacturers in a broad range of industries, such as automotive, medical and consumer technologies.

Founded in 1949, the Fraunhofer-Gesellschaft currently operates 76 institutes
and research units throughout Germany.

Role in the project

Fraunhofer IMWS provides high resolution material characterization for improving and securing reliability by identifying process induced defects and exploring relevant failure modes and degradation mechanisms during device operation. We will investigate power and RF HEMT devices to identify related structural degradation during operation using defect localization, advanced site-specific sample preparation and high-resolution transmission electron microscopy as well as secondary ion mass spectroscopy techniques to identify root causes and degradation mechanisms. Structural and chemical observations will be correlated to electrical performance and local defects in order to improve device performance and reliability. Furthermore, Fraunhofer-IMWS will perform microstructural characterization and micro-mechanical testing of advanced interconnect and packaging technologies for GaN packaging to optimize the structure related material properties and secure the reliability of the devices. The Fraunhofer IAF is participating as a partner in WP3. In the context of this work package, a lateral GaN-on-Silicon High Electron Mobility Transistor technology is to be developed, which can be used to demonstrate integrated mm-wave circuits up to 28 GHz. This includes the active device development characterization and modelling.

The Fraunhofer IAF also participates in WP5, which is focusing on the detailed reliability analysis of the developed GaN-devices. The target is to increase the performance of the devices regarding their breakdown and lifetime capability. Within WP6, the IAF will design mm-wave integrated power amplifiers, targeting an application frequency of 28 GHz. Both, the IFAGs GaN-on-Si and the competing IAFs GaN-on-SiC MMIC technology, will be used for circuit design to demonstrate a high backoff efficiency.

Fraunhofer IZM participates in WP4 with focus on wafer level packaging of RF power GaN semiconductors up to 28 GHz and fine pitch bonding to PCB substrates with low thermal resistance and improved reliability. In WP5 Fraunhofer IZM will perform reliability tests and qualification of assembled RF power GaN on PCB.

Key contribution

Fraunhofer IMWS complements the quality and reliability investigations of GaN on Si semiconductor components by providing and applying advanced physical failure diagnostics approaches. Material Characterization of advanced interconnects to enable advanced GaN packaging will be caried out by us. We also support GaN device technology developments with our expertise in exploring and understanding of material interactions and failure mechanisms. We will provide adapted failure analysis methods, nanoanalytics and reliability models as an important input for developing and optimizing process steps, as well as to assure yield and quality during manufacturing and ultimately to secure reliability during application.

Fraunhofer IAF complements the development of the RF GaN-on-Si devices with its long experience in III-V based semiconductor research, including its extensive high frequency measurement and modeling capabilities. Within the framework of the reliability analysis, the Fraunhofer IAF will assemble test structures of the lateral high-frequency devices and will evaluate their high-frequency excitation under high compression for different bias points and temperatures. The results of these investigations serve to optimize the active components within the development process. By providing its in-house GaN/SiC technology as a benchmark for the circuit design, the IAF enables the best possible comparison to evaluate the newly developed GaN-on-Si technology.

Fraunhofer IZM develops the assembly of RF GaN components on PCB substrates. Bumps of silver-gold alloy are electroplated in patterned resist on GaN wafer. By chemical dealloying an open-porous gold sponge is fabricated as bump interconnects. The highly compressible nanoporous gold will be used for flip chip integration of GaN to PCB by low temperature, low pressure thermocompression bonding. The application of pre-applied underfiller on GaN wafer will be developed to further improve bonding, thermal heat dissipation and reliability.