0.5 TeraHertz Silicon-Germanium Heterojunction Bipolar Transistor

A European consortium recently started its DOTFIVE project. The consortium plans to develop advanced silicon-based bipolar transistors with a maximum operating frequency of 0.5 THz (0.5 TeraHertz or 500 GigaHz) needed for future millimeter wave and terahertz communication, radar, imaging and sensing applications. DOTFIVE is aiming to establish a leadership position for the European semiconductor industry in the area of SiGe HBTs (Silicon-Germanium Heterojunction Bipolar Transistors) for millimeter wave applications, where semiconductor manufacturers like STMicroelectronics and Infineon Technologies are already involved.

DOTFIVE technology intends be a key enabler for silicon-based millimeter wave circuits penetrating the so-called THz gap, enabling enhanced imaging systems with applications in the security, medical and scientific area.

Today’s state-of-the-art SiGe HBTs achieve a maximum operating frequency of about 300 GHz at room temperature. The DOTFIVE project has set its goal at 500 GHz at room temperature, a performance usually thought only possible with III-V compound semiconductor technologies. A higher operating speed can open up new application areas at very high frequencies, or can be traded in for lower power dissipation, or can help to reduce the impact of process, voltage and temperature variations at lower frequencies for better circuit reliability. SiGe HBTs are key devices for high-frequency low-power applications. Compared to III-V compound semiconductor devices, they enable high density and low-cost integration making them suitable for consumer applications.

In order to achieve their goals, the DOTFIVE partners will team up for research and development work on silicon-based transistor architectures, device modeling, and circuit design. The project involves 15 partners from industry and academia in five countries:

  • Infineon Technologies (Germany) and STMicroelectronics (France) are capable of manufacturing 250 GHz HBTs on silicon and willing to push up to 500 GHz by working on structural and technological improvements
  • IMEC (Belgium) and IHP (Germany), two research institutes working on innovative HBT concepts, new process modules and transistor structures on silicon wafers
  • XMOD Technologies (France) and GWT-TUD (Germany), two small and medium enterprises (SMEs) capable of providing needed parameter extraction and RF device modeling expertise
  • Seven academic partners – the Johannes Kepler University of Linz (Austria), the ENSEIRB (Ecole Nationale Supérieure d’Electronique, Informatique et Radiocommunications de Bordeaux), the Paris-Sud University (France), the Technical University of Dresden (Germany), the Bundeswehr University in Munich( Germany), the University of Siegen (Germany), the University of Naples (Italy) – with a strong understanding of nano-transistors, simulation, modeling and characterization of devices as well as design of RF electronic functional blocks. ALMA (France) is in charge of all administrative and financial aspects of the project.