Proton irradiation effects on GaN nanoscale vacuum electron diodes

Vacuum tubes are well known for their resilience under radiation environments, but are bulky, non-integrated, and power hungry. We recently demonstrated high performance, low voltage turn-on GaN nanogap vacuum electron diodes which realize a vacuum electron device architecture on an on-chip GaN-based platform. Here, we present initial studies of radiation effects on the performance and reliability of these devices, focusing on proton irradiation. No significant change on the device performance under a very high dose of radiation exposure, up to 600 MRad, using 2.5 MeV protons was observed. In contrast, prior radiation studies of state of the art GaN PiN diodes show degradation beginning at more than two orders of magnitude lower exposure dose of 2.5 MeV protons. We will present experimental and modeling studies of effect of radiation exposure on the GaN vacuum diode field emission behavior which shed light into potential radiation damage mechanisms for this new class of devices.