Air Force Institute of Technology Wright-Patterson Air Force Base United States
Ten aluminum gallium nitride AlGaNgallium nitride GaN high-electron mobility transistors HEMTs were irradiated with 1.7 MeV germanium Ge ions using the Micrometer Resolution Optical, Nuclear, and Electron MicroscopeMicro-ONE system on the high-voltage engineering HVE 6 MV tandem accelerator at Sandia National Laboratories. Using the Micro-ONE system enabled targeting of the gate-drain gap of the transistors with the ions. In situ measurements captured degradation in the on and semi-on bias conditions after varying levels of ion fluence targeted in the gap region no change to the off-bias condition was observed during in situ measurement. Pre- and post-irradiation output and transfer performance measurements including threshold voltage, transconductance, drain current, and gate diode characteristics were compared and analyzed. Changes to these performance characteristics in the on, off, and semi-on bias conditions included decreased transconductance, decreased drain current, and changes to the diode characteristics, but with no change to the threshold voltage. A delayed response between the start of the ion irradiation and an increased degradation in gate current was observed for both the on and semi-on-state bias. A delayed response between the start of ion irradiation and an increased degradation in drain current was also observed for the semi-on-state bias. Immediate degradation to the drain current during irradiation was observed in the on-state bias. These observed changes to the AlGaNGaN HEMT device characteristics during 1.7 MeV Ge ion irradiation are correlated to similar performance degradation mechanisms observed in previous AlGaNGaN HEMT reliability studies.
Journal Article - Open Access
Journal of Radiation Effects Research and Engineering , 38, 1, 01 Jan 0001, 01 Jan 0001,