Heavy ions irradiation effects on AlGaN/GaN high electron mobility transistors

AlGaN / GaN high electron mobility transistors (HEMTs) were exposed to 800MeV Bi ions with fluence up to 5×10
⁷
ions/cm
²
at the Heavy Ion Research Facility in Lanzhou (HIRFL) Cyclotrons in Institute of Modern Physics, Chinese Academy of Sciences. Test results show that the drain current I
_d
and the maximum transconductance g
_max
decreased by 6.8 % and 3.2% respectively, while the gate leakage current increased more than five times, and the gate-lag increased dramatically too. After restoring in room temperature for three months, output characteristics recovered to almost the same as its original values before irradiation, the transfer characteristics and the gate-lag showed partial recovery, while the gate leakage current had no annealing effects. The analysis demonstrate that radiation induced traps would decrease the electron density of the two-dimensional electron gas (2DEG) further to influence the output and transfer characteristics. Moreover, swift heavy ions produced latent tracks along the ion trajectories through the hetero-junction, these latent tracks decrease the gate performance.