Recessed-Gate structure approach toward normally off high-voltage AlGaN/GaN HEMT for power electronics applications

The recessed-gate structure approach is very effective for realizing normally off high-voltage AlGaN/GaN HEMTs because the gate threshold voltage can be controlled by the etching depth of the recess without significant increase in on-resistance characteristics. Most of the AlGaN/GaN HEMTs demonstrated have, normally during depletion mode, characteristics with gate threshold voltage and with enhancement mode characteristics strongly required for the power electronics applications.