Electrical characteristics of post-gate-annealed AlGaN/GaN HEMTs on sapphire substrate

AlGaN/GaN HEMTs were post-gate-annealed at 300°C for 2 min and longer. DC characteristics of AlGaN/GaN HEMTs as a function of annealing cycle duration were studied. Improvement in HEMT parameters such as drain source saturation current, transconductance, gate leakage current and off-state breakdown voltage (V
_boff
) was observed with increase in annealing duration. This was correlated with surface/interface traps removal, leading to improvement in access region resistance between source-drain and gate drain regions.