GaN Transistor Bests Silicon

A new gallium nitride (GaN) -based transistor, the first GaN metal/oxide semiconductor field-effect transistor (MOSFET) of its kind, performs better than silicon transistors in high-power and high-temperature electronics.

Rensselaer Polytechnic Institute doctoral student Weixiao Huang invented the new transistor, which could reduce energy consumption and improve the efficiency of power electronics systems in everything from motor drives and hybrid vehicles (it has captured the attention of some American and Japanese auto companies) to house appliances and defense industry equipment.

Weixiao Haung with his new GaN transistor. (Photo courtesy Rensselaer Polytechnic Institute)

“Silicon has been the workhorse in the semiconductor industry for the last two decades,” said Huang, the son of farmers in rural China. “But as power electronics get more sophisticated and require higher performing transistors, engineers have been seeking an alternative like gallium nitride-based transistors that can perform better than silicon and in extreme conditions.”

Most households contain dozens of silicon-based electronics. An important component of each of those electronics is usually a silicon-based transistor known as a silicon MOSFET. To convert the electric energy to other forms as required, the transistor acts as a switch, stopping or starting the flow of current through the device.

Huang said he first developed a new process that demonstrates an excellent GaN MOS (metal/oxide/GaN) interface. Engineers have known that GaN and other gallium-based materials have some extremely good electrical properties, much better than silicon. However, no useful GaN MOS transistor has been developed. His innovation has already shown world-record performance, according to Huang.

In addition, he has shown that his transistor can integrate several important electronic functions onto one chip like never before. “This will significantly simplify entire electronic systems,” Huang said. He has also designed and experimentally demonstrated several new novel high-voltage MOS-gated FETs that have shown superior performance compared to silicon MOSFETs in terms of lower power consumption, smaller chip size, and higher power density.

The new transistors can greatly reduce energy loss, making energy conversion more efficient. “If these new GaN transistors replaced many existing silicon MOSFETs in power electronics systems, there would be global reduction in fossil fuel consumption and pollution,” Huang said.

The new GaN transistors can also allow the electronics system to operate in extremely hot, harsh, and high-power environments and even those that produce radiation. “Because it is so resilient, the device could open up the field of electronic engineering in ways that were not previously possible due to the limitations imposed by less tolerant silicon transistors,” he said.

Huang has published more than 15 papers during his time as a doctoral student in the Department of Electrical, Computer, and Systems Engineering. He received a bachelor’s in electronics from Peking University in Beijing in 2001 and a master’s in physics from Rensselaer in 2003. He will receive his doctorate from Rensselaer May 17 and plans to work as a device engineer in the semiconductor industry.

For more information, visit: www.rpi.edu