Yale University

Yale University will conduct a comprehensive investigation to overcome the barriers in selective area doping of gallium nitride (GaN) through an epitaxial regrowth process for high-performance, reliable GaN vertical transistors. Transistors based on GaN have emerged as promising candidates for future high efficiency, high power applications, but they have been plagued by poor electrical performance attributed to the existing selective doping processes. The team will demonstrate vertical GaN diodes through a selective area regrowth processes with performance similar to those made using current in situ techniques, which are non-selective and therefore less flexible. Key innovations in this project will be to use three-dimensional nanoscale characterizations to understand the regrowth interface formation at the nano scale, and to apply atomic-level manipulation to control impurities, and suppress extrinsic and intrinsic defects at the selective area regrowth interface. This will enable the electronic characteristics of the selective area growth p-n junction active region to be customized allowing for high performance GaN vertical transistors. The successful production of reliable and high-performance GaN vertical transistors on bulk substrates will be transformative to many mid-voltage applications including photovoltaic inverters, motor control, and hybrid automotive.

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.