Electrothermal reliability challenges and mitigation in III-V transistors for next-generation wireless and wireline communication

Emerging wireless standards such as 6G aim for data rates above 1 Gbit/s, enabling advances in sensing, AI, AR/VR, and remote healthcare. Achieving these speeds requires sub-THz carrier frequencies (90–300 GHz), which increase system complexity and power consumption. At the same time, wireline communication, driven by cloud, AI, and data-center workloads, is pushing toward multi-hundred-Gb/s electrical and optical interconnects. Both domains face similar device-level challenges: solid-state amplifiers, especially power amplifiers (PAs) in wireless and high-speed drivers in wireline, suffer declining efficiency beyond 100 GHz, demanding innovations in materials and devices. Compound semiconductors (e.g., GaAs, InP) can improve efficiency compared to Si-CMOS, but large-scale manufacturing of these devices is challenging. One promising solution is integrating these group III-V semiconductors on large-area silicon substrates, offering cost and sustainability benefits.

With this aim, at imec, we have been developing III-V transistors on a Si platform with innovative integration technologies. However, integration of III-V transistors on silicon can lead to increased defectivity and thermal challenges. As a PhD researcher, you will focus on understanding and proposing solutions to mitigate these challenges for InP and GaAs heterojunction bipolar transistors (HBTs) integrated on Si substrates. Areas of focus will be on:

• Exploring the HBT design space by developing electrothermal characterization and physics-based models (using TCAD)
• Propose innovative designs to improve electrothermal reliability of the devices also considering the overall system optimizations
• Study the impact of electrothermal effects on large-signal performance of the advanced HBTs.
• A comparative performance benchmark of proposed devices against state-of-the-art transistor technologies.

As a device researcher, you will work at the intersection of material science, semiconductor physics, and circuit design acquiring unique skillset to make impact on this vibrant research field.