Centennial Researchers Boost Potential For Gallium Nitride Electronics

Feb. 2, 2011 - PRLog -- Gallium nitride (GaN) material holds promise for emerging high-power devices that are more energy efficient than existing technologies – but these GaN devices traditionally break down when exposed to high voltages. Now researchers on NC State University's Centennial Campus have solved the problem, introducing a buffer that allows the GaN devices to handle 10 times greater power.

“For future renewable technologies, such as the smart grid or electric cars, we need high-power semiconductor devices,” says Merve Ozbek, a Ph.D. student at NC State and author of a paper describing the research. “And power-handling capacity is important for the development of those devices.”

By implanting a buffer made of argon, researchers have created GaN devices that can handle 10 times as much power.

Previous research into developing high power GaN devices ran into obstacles, because large electric fields were created at specific points on the devices’ edge when high voltages were applied – effectively destroying the devices. NC State researchers have addressed the problem by implanting a buffer made of the element argon at the edges of GaN devices. The buffer spreads out the electric field, allowing the device to handle much higher voltages.

The researchers tested the new technique on Schottky diodes – common electronic components – and found that the argon implant allowed the GaN diodes to handle almost seven times  higher voltages. The diodes that did not have the argon implant broke down when exposed to approximately 250 volts. The diodes with the argon implant could handle up to 1,650 volts before breaking down.

“By improving the breakdown voltage from 250 volts to 1,650 volts, we can reduce the electrical resistance of these devices a hundredfold,” says Dr. Jay Baliga, Distinguished University Professor of Electrical and Computer Engineering at NC State and co-author of the paper. “That reduction in resistance means that these devices can handle ten times as much power.”

The paper, “Planar, Nearly Ideal Edge Termination Technique for GaN Devices,” is forthcoming from IEEE’s Electron Device Letters. The research was supported by NC State’s Future Renewable Electric Energy Delivery and Management Systems Center, with funding from the National Science Foundation.

NC State’s Department of Electrical and Computer Engineering is part of the university’s College of Engineering, which is located on Centennial Campus.

Written by Matt Shipman, NCSU News Services

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About Centennial Campus and NC State University
Centennial Campus (http://www.centennial.ncsu.edu) is an internationally recognized 1,314-acre research park and technology campus owned and operated by North Carolina University. Home to more than 60 corporate, government and non-profit partners, such as Red Hat, ABB, and the USDA, collaborative research projects vary from nanofibers and secure open systems technology to serious gaming and biomedical engineering. Four university college programs also have a significant presence on campus – College of Engineering, College of Veterinary Medicine, College of Textiles and the College of Education. NC State is one of the top research universities in the country, with expenditures in research approaching more than $325 million annually. The university ranks third among all public universities (without medical schools) in industry-sponsored research expenditures. (http://www.ncsu.edu)