This article was originally featured in the edition:

Improving The Performance Of Power Transistors


Researchers at IEDM offers insights into how to make GaN transistors switch faster, produce higher blocking voltages, exhibit a very low on-resistance and completely suppress dynamic on-resistance by Richard Stevenson

There is still much work to do to improve the performance of the GaN power transistor. While its commercialisation is netting sales, far greater revenues could follow if this device switches more efficiently, handles higher voltages and currents, and offers greater stability.

Options for succeeding on all these fronts were outlined at the recent International Electron Devices Meeting (IEDM), held in San Francisco from 2-6 December 2017. At that gathering researchers detailed: improvements in the switching performance of transistors that feature a gate insulator over the junction; the tremendous capability of vertical power transistors with fins and trenches; and the elimination of dynamic on-resistance through proton irradiation.

Speedier switching

A device architecture for providing superior switching was presented by Satoshi Nakazawa from Panasonic Corporation. Working with colleagues from Osaka University and Hokkaido University, he and his co-workers developed a GaN transistor with an AlON gate insulator that combines fast switching with a low leakage current.

"The proposed device exhibits a two-to-four times faster switching speed compared to a typical silicon super-junction-MOS with the same drain current rating," says Nakazawa. "This suggests a reduction in switching loss to half or less in high-frequency switching operations."