High Temperature Performance and Heterogenous Integration of AlGaN/GaN HEMTs for Power Electronics
Power integrated circuits (PICs) for extreme-temperature applications, such as space exploration (e.g., Venus) and advanced automotive systems, require devices capable of reliable operation under harsh conditions.
Overview
Gallium nitride (GaN) high-electron-mobility transistors (HEMTs) are ideal candidates for these ICs due to their exceptional properties, including high breakdown voltage, high electron mobility, and thermal stability. However, operating GaN HEMTs at elevated temperatures poses challenges, including high gate leakage currents and threshold voltage instability, which can compromise the electrical stability and reliability of PICs.
This presentation highlights the state-of-the-art performance of devices and integrated circuits based on wide-bandgap semiconductors, such as GaN and SiC, for operation in harsh environments. Novel gate stack design techniques are discussed to address these challenges and enable high-temperature operation of GaN HEMTs up to 450°C. To further enhance PIC performance in extreme environments, we developed an "interposer" style integration of an In₂O₃ FET-based gate driver with GaN HEMTs on a Si substrate, achieving stable operation at temperatures up to 125°C.
Presenters
Brief Biography
Mritunjay Kumar is a Ph.D. candidate in Electrical Engineering at King Abdullah University of Science and Technology (KAUST), Saudi Arabia, under the supervision of Prof. Xiaohang Li. Before joining KAUST, he earned his Master of Technology from the Indian Institute of Technology (IIT) Dhanbad. His research focuses on developing advanced wide-bandgap semiconductor devices for extreme-temperature power electronics applications, addressing challenges such as threshold voltage instability and high gate leakage currents in GaN HEMTs through innovative materials and gate design techniques.
Mritunjay has made significant contributions to the field of power electronics for extreme temperature, as evidenced by publications in reputed journals such as Applied Physics Letters (APL) and Japanese Journal of Applied Physics (JJAP). His achievements include the development of a high-threshold voltage (7.4 V) enhancement-mode GaN HEMT and the implementation of bi-layer gate stacks for stable operation at temperatures up to 450°C. His work also explores heterogeneous integration, such as combining GaN HEMTs with indium oxide-based driver circuits and gallium oxide transistors, demonstrating stable operation in harsh environments.