Fast Neutron Irradiation Effects on Multiple Gallium Nitride (GaN) Device Reliability in Presence of Ambient Variations

Radiation-hard semiconductor devices are becoming more important for a growing number of nuclear and space applications. Gallium Nitride (GaN) semiconductor devices can be highly beneficial in this regard. In this paper, we report the electrical performance of multiple AlGaN/GaN deep UV LEDs irradiated by high fluence fast neutrons. The irradiation experiment was conducted in a newly enhanced beamline at the Los Alamos Neutron Science Center (LANSCE) from 2014-2016 with a maximum fluence of 2.41x1013 neutrons/cm2 over a 3-year span, in an temperature varying, semi-open outdoor housing. We continuously monitored the I-V characteristics of all GaN devices, and showed that they maintained proper I-V behaviors as the neutron fluence increased. Extensive data analysis further shows that effects of neutron irradiation fluence increment in a given day are actually smaller than that induced by daily temperature variation. Our experimental results facilitate the design of diagnostics systems such as multi-pixel imagers for high energy density physics experiments, and complex space electronics that must survive through both high fluence radiation and large orbital temperature variations.