Neutron irradiation effects on metal-gallium nitride contacts

Abstract

We have measured the effect of fast and thermal neutrons on GaN Schottky barriers and ohmic contacts using current-voltage and transmission line method electrical techniques, optical, atomic force and scanning electron microscopy morphological techniques, and X-ray photoemission spectroscopy chemical techniques. These studies reveal a 1015n/cm2 neutron threshold for Schottky barrier ideality factor increases, a 10 15n/cm2 fast plus thermal neutron threshold for ohmic contact sheet and contact resistance increases, and 1016n/cm 2 neutron fluence threshold for major device degradation identified with thermally driven diffusion of Ga and N into the metal contacts and surface phase changes. These results demonstrate the need for protecting metal-GaN contacts in device applications subject to neutron radiation. © 2014 AIP Publishing LLC.