An article published by Patrick Fay, professor of electrical engineering, and member of the Wireless Institute at the University of Notre Dame, was featured on the cover of the February journal issue of physica status solidi (a) – applications and materials science (pss), a core journal in the field of nitride semiconductor materials and devices for more than two decades. The results published by Fay and his collaborators are among the latest discoveries in the industry. “This article describes an interesting approach for realizing vertical GaN-based pn diodes. Both epitaxial lift-off and device isolation by implantation are quite challenging approaches which have been nicely mastered by the authors,” said Ferdinand Scholz, a pss editorial advisory board member and deputy head of the Institute of Functional Nanosystems, Optoelectronics Division at the University of Ulm in Germany.
In the paper, Fay’s group established that the process of epitaxial lift-off, can be used to make devices in GaN, lift them off of the original substrate–in a foil–and then transfer them onto another substrate or heatsink. This process does not compromise the device performance, despite the added handling and processing complications. The team was also able to prove that this method can improve how the devices dissipate heat, improve efficiency and reduce cost. Possible applications for this technology could be in any industry where power conversions are performed, such as data centers, industrial motor controls, factories or in electric vehicles.
“This work on epitaxial lift-off and transfer of GaN-based power electronics has been both interesting and rewarding,” commented Fay. “Interesting because there have been many research challenges to overcome. Rewarding because we find that the high electrical performance can be maintained while significantly improving the thermal performance as well as potentially, significantly reducing the cost.”