Sandia National Laboratories

Vertical transistors based on bulk gallium nitride (GaN) have emerged as promising candidates for future high efficiency, high power applications. However, they have been plagued by poor electrical performance attributed to the existing selective doping processes. Sandia National Laboratories will develop patterned epitaxial regrowth of GaN as a selective area doping processes to fabricate diodes with electronic performance equivalent to as-grown state-of-the-art GaN diodes. The team’s research will provide a better understanding of which particular defects resulting from impurities and etch damage during the epitaxial regrowth process limit device performance, how those defects specifically impact the junction electronic properties, and ultimately how to control and mitigate the defects. The improved mechanistic understanding developed under the project will help the team design specific approaches to controlling impurity contamination and defect incorporation at regrowth interfaces and include development of in-chamber cleans and regrowth initiation processes to recover a high-quality epitaxial surfaces immediately prior to crystal regrowth.

If successful, PNDIODES projects will enable further development of a new class of power converters suitable in a broad range of application areas including automotive, industrial, residential, transportation (rail & ship), aerospace, and utilities.