CIES Consortium

National Projects

NEDO project

Next generation power electronics project to realize low-carbon society
(Development of GaN power device technology)

This project started in 2017, and pursues higher operation frequency achieved by GaN high electron mobility transistors (HEMTs) enabling them to be used in the 5G mobile communication systems. For this purpose, the study is focused on nitrogen (N) polar GaN HEMT material system.
Most of the GaN HEMTs currently available and under developed are made using Ga-polar GaN material system. In Ga-polar GaN HEMTs, ohmic electrodes and the carrier electrons are connected through the AlGaN barrier layer. This could increases the on-state resistance of the HEMTs.
The N-polar GaN HEMTs, on the other hand, enable the GaN channel layer located on the top of the semiconductor layers. This will reduce the contact resistance and enhance the gate controllability, both of which help improve the high-frequency performance of the HEMTs.