The Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik (FBH) is part of the Research Fab Microelectronics Germany (FMD) and contributes its expertise in the development of energy-efficient semiconductor components. Conducted research revolves around novel materials and development of necessary components for applications such as electromobility, Industry 4.0 or the mobile communication of the future.

Dr. Yacoub, you conduct research in the field of III/V electronics and are head of the InP Devices Lab at FBH. What do you expect from indium phosphide?

The future communications standard 6G targets frequencies above 100 GHz. This places new demands on hardware as well as high-frequency electronics, which has consequences for the choice of semiconductors. Hetero-bipolar transistors (HBT) based on the semiconductor indium phosphide (InP) are compact thanks to their high integration capability and deliver excellent power densities, high operating voltage and thus, compared to silicon-based technologies, high output power. Together with multiple thin-film routing layers, complex monolithic integrated circuits can be realized on a small area. However, such circuits are very challenging in terms of technology and process since they must be extremely scaled. In other words, they have to offer more power on a smaller area – while maintaining the same yield.

How can you solve this challenge?

Clearly with high-performance fabrication infrastructure. In order to master the technological requirements, FBH has upgraded its facilities in the clean room accordingly as part of the Research Fab Microelectronics Germany. With state-of-the-art e-beam lithography, structure sizes as small as 30 nm are possible. Additionally, fully automated high-tech equipment for etching or electroplating not only increases the yield and homogeneity of the circuits, but also the wafer throughput.

What opportunities does this create for your research area?

The new, high-performance infrastructure will be used in various national and European projects. One of these is the ULTRAWAVE project, in which a consortium is developing a novel wireless system architecture for communications with improved network coverage and unprecedented data rates. FBH is supplying the monolithic integrated circuits required for this purpose, which are based on the in-house InP DHBT process. Thanks to a point-to-multipoint infrastructure in the D-band at 140 GHz, the system architecture offers 100 Gbps within a radius of one square kilometer. This will be achieved for the first time in a test trial in Valencia – point-to-point systems in the same frequency band have already been demonstrated by other groups in initial trials. The ULTRAWAVE system uses standard modem access and enables wireless data transmission of up to one kilometer.

Hady Yacoub studied electrical engineering at the German University of Cairo and microelectronics and communications engineering at the University of Ulm. After completing his master’s degree in 2011, he received his PhD from RWTH Aachen University in 2017, focusing on III-V semiconductor-based devices for high power and high frequency applications. Hady Yacoub joined the Ferdinand-Braun-Institut in Berlin as a postdoctoral researcher in 2018 and has been leading the InP Devices Lab there since 2019. He is author and co-author of more than 20 papers in the field of III-V semiconductors.