Towards the limits of GaN electronics: Technologies for low resistance, high breakdown voltage and improved thermal management
The outstanding properties of Gallium Nitride semiconductors for power electronic devices can enable significantly more efficient and compact future power converters. Despite the outstanding recent progress, the performance of current GaN power devices is still far below the limits of this material. Further improvements require the reduction of the on-resistance, while maintaining large voltage-blocking capabilities, and an improved thermal management, which will enable higher efficiency, larger power density and smaller devices.
To address these challenges, this talk will discuss the introduction of nanostructures to power devices, such as slanted tri-gates, which yield superior channel control and spread efficiently the lateral electric fields inside the device, resulting in a much larger breakdown voltage, improved sub-threshold slope and in an exponential reduction of the reverse leakage current.
To drastically increase the electric conductivity of these devices, and thus reduce their losses, a multi-channel platform will be presented consisting of multiple parallel 2DEG embedded channels, simultaneously modulated by tri-gate structures, resulting in a significant reduction of the sheet resistance. The tri-gate provides an effective way to tunethe threshold voltageand even reach E-mode operation in the multi-channel structure by narrowing the tri-gate fins, leading to the demonstration of high performance power MOS HEMTs and Schottky Barrier Diodes.
Finally, GaN vertical devices will be presented on cost-effective large-scale Silicon substrates, along with integrated technologies to improve thermal management, which unveil the full potential of GaN materials for power electronics.
BIO: Elison Matioli is an assistant professor in the institute of electrical engineering at Ecole Polytechnique Fédérale de Lausanne (EPFL). He received a B.Sc. degree in applied physics and applied mathematics from Ecole Polytechnique (Palaiseau, France) in 2006 and a Ph.D. degree from the Materials Department at the University of California, Santa Barbara (UCSB) in 2010. He was a post-doctoral fellow in the EECS department at the Massachusetts Institute of Technology (MIT) until 2014. He has received the UCSB Outstanding Graduate Student - Scientific Achievement Award for his Ph.D. thesis, the IEEE George Smith Award, the SNSF Assistant Professor Energy Grant Award, and the ERC Starting Grant Award.