Gallium nitride transistor could replace silicon

Gallium nitride transistor could replace silicon
A microscopic image of a small gallium nitride-based device, which can be easily scaled up for higher current handling capability. Image: Junxia Shi

( -- A Cornell researcher has created an extremely efficient transistor made from gallium nitride, which may soon replace silicon as king of semiconductors for power applications.

A Cornell researcher has created an extremely efficient transistor made from a material that may soon replace silicon as king of semiconductors for power applications.

Junxia Shi, a graduate student in the laboratory of Lester Eastman, the John Given Foundation Professor of Engineering, developed the gallium nitride-based device, which could form the basis for the circuitry in products from laptops to hybrid vehicles to windmills to other power electronic systems.

The patent-pending device is a basic electrical switch made from the compound , a material with unique that Eastman and colleagues have been studying for more than a decade. Research on their recent breakthrough was published July 28 in the journal .

The new transistor's on-resistance, or measure of resistance to electric current, is 10 to 20 times lower than today's silicon-based power devices. It also has a high breakdown voltage, which is a measure of how much voltage can be applied across a material before it fails.

The key to the device lie in gallium nitride's low , causing less power loss to heat, and its ability to handle up to 3 million volts per centimeter without electrical failure. Silicon, a competing material, can handle only about 250,000 volts per centimeter.

At the heart of improving electronics, Eastman said, is the ability to make devices that can switch electricity from high voltage to high current, which is a measurement of electrical applicability, while minimizing power loss.

"Power has to go from A to B in a machine with a high voltage transmission line to minimize power loss," Eastman said. "Before now, there were no that could handle both high current and the , but our device can do it."

Gallium nitride transistor could replace silicon
A larger version of a gallium nitride transistor. Image: Junxia Shi

The transistors, which were made with Cornell nanofabrication equipment, might one day power everything from hybrid electric vehicles to Navy destroyers. In fact, the U.S. Navy first funded Cornell's research into gallium nitride more than 10 years ago and is a major funder of Eastman's research today.

In next-generation electrical devices, "you want to have the power that's coming out to be not much less than the power that's going in," Eastman said. "This is the best material we know of that can do this conversion without loss of energy."

Shi and Eastman have a provisional patent on their device. The New Jersey-based company Velox and Motorola spinoff Freescale have also helped fund the research, with the hope of producing the devices at an industrial scale.

Provided by Cornell University (news : web)

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Citation: Gallium nitride transistor could replace silicon (2009, December 8) retrieved 22 October 2019 from
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Dec 08, 2009
How expensive is Gallium and how much of it is available?

Dec 09, 2009
Since the semiconductor industry is geared to using silicon, they will wait until this new gallium technology is mature. Even then -should new silicon technology reduce the gap in performance a bit- the industry might choose to stay with silicon for cost reasons.

Dec 09, 2009
As the navy is involved I suspect there are applications for powered weapon systems that silicon is not suited for. Think rail guns and lasers and emp-hardened systems.

Dec 09, 2009
Exactly, Sanescience, these are not intended for PCs, but for phased array radar systems. So you can all quit complaining about how they will never be commercialized because of cost -- they aren't supposed to be commercialized by Intel, only by Ratheon.

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