A Path Towards III-Nitrides-Based Superjunction Devices

Zlatko Sitar
Leda Lunardi

Project runs from 08/01/2016 to 07/31/2020
$380,000

The proposed research will extend the applicability of wide bandgap semiconductors beyond the traditional limits imposed by the unipolar (Baliga’s) figure of merit by demonstrating a path to superjunction structures based on novel doping and defect control processes. This will lead to a new generation of devices that take advantage of the expected capabilities of III-nitrides but are not limited by doping or implantation technology. Superjunction device structures based on AlGaN are proposed where they exploit the doping selectivity observed in different III-nitride polar domains and the lateral polar patterning technology developed at the WideBandgaps Laboratory at NCSU. In addition, further control of point defects will be realized through the use of Fermi level control schemes based on engineered illumination by the use of UV (blue) lasers surface selective during the growth of the device structure. Such structures will eventually allow for significant breakdown voltages exceeding 5 kV and significant low on-resistance, beyond the expected rated BFOM. This research will provide for a transformative and disruptive technology for power electronics and also provide a breakthrough technology for other applications such as efficient deep UV emitters for water purification. The successful demonstration of such disruptive technology would revolutionize energy switching and transmission, energy storage, and related applications in electrical motor drives and other power intensive applications within the US. As such, the White House has recognized the need to build America’s leadership in this technology as part of the manufacturing innovation institutes. In general, this research will directly lead to materials that will be used for applications that deal with the preservation and extension of natural resources by: (1) allowing for the efficient 
use and transmission of electrical energy, (2) availability of clean potable water through 
disinfection by the use of UV, and (3) the detection of pollutants and other effluents. This 
program will provide the opportunity to educate a Ph.D. student with support from an undergraduate student on the growth and characterization of wide bandgap materials while participating with the group’s international collaborators network.