Effect of oxygen annealing temperature on AlGaN/GaN HEMTs

We have investigated an effect of oxygen annealing temperature on the leakage current and breakdown voltage of AlGaN/GaN HEMTs. The breakdown voltage of 830 V and a low drain leakage current of 1.2 nA/mm at V_DS= 50 V and V_GS= -5 V are exhibited by employing oxygen annealing at 550°C. The blocking characteristics are improved with increasing annealing temperature up to 550°C due to high density of deep traps generated by oxygen annealing. However, the blocking characteristics of the annealed device were degraded when the annealing temperature exceeds 550°C due to thermal damage on the surface of AlGaN/GaN HEMTs.