Home News & Analysis Analysis GaN nanoelectronics-transistor blocking voltage exceeds 1kV

GaN nanoelectronics-transistor blocking voltage exceeds 1kV

Low resistance resulting in reduced power consumption and heating have attracted researchers to study GaN systems for nanoelectronics. Previous work has focused on laterally oriented GaN and AlGaN transistors, which readily provide a high mobility and low resistance. However, these structures are limited in terms of the break-down and threshold voltage that can be achieved without compromising device size, which may make them unsuitable for automobile applications. Now Tohru Oka and colleagues at the Research and Development Headquarters for TOYODA GOSEI in Japan show how they can overcome these limitations.

Analysis

24 August 2015

byNews Desk

Oka and his team adopted the vertical orientation. Previous work has already shown that in this orientation the breakdown voltage can be increased by increasing the drift region thickness without compromising the device size. However, so far these structures have still been limited in the blocking voltage that the device can withstand while maintaining a low on-resistance.

“We redesigned the thicknesses and doping concentrations of channel and drift layers to reduce the resistances of the epitaxial layers while maintaining a blocking voltage of over 1.2kV,” said Oka and colleagues in the report of their work. They also used hexagonally shaped trench gates to increase the gate width per unit area thereby reducing the specific on-resistance. “These led to the excellent performance of 1.2kV-class vertical GaN MOSFETs with a specific on-resistance of less than 2mΩ cm².”