University of Missouri

The University of Missouri will develop neutron transmutation doping of GaN to fabricate uniform heavily doped n-type GaN wafers. GaN has long been proposed as a superior material for power electronic devices due to the intrinsic material advantages such as greater breakdown voltages and greater stability. Unfortunately, the fabrication of GaN wafers with uniform and high levels of dopants is challenging due to a lack of sufficient control during the existing crystal growth methods. The neutron transmutation doping process, which consists of exposing GaN wafers to neutron radiation to create a stable network of the dopant germanium within the GaN wafer, allows for a greater degree of precision and results in a high level, uniform doping concentrations across the wafer. With this method, repeatable production of high quality GaN substrates may be achieved. Specific innovations in this proposal concern an in-depth study of neutron transmission doping and a characterization of the resulting wafer, including analyzing resistivity, dopant concentration, unwanted impurities, and damage to the GaN lattice.

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.