An Enhancement-Mode Algan/GaN HEMT with Island-Ohmic p-GaN Featuring Stable Threshold voltage and Large Gate Swing

A novel AlGaN/GaN HEMT based on an Island-Ohmic p-GaN gate (IO-PGaN) structure is proposed. Thanks to the Island-Ohmic, the “floating” p-GaN is connected with the gate terminal via the heavily doped p++-GaN island. Therefore, the net charges generated in the p-GaN region under the gate or drain stress conditions, could be easily compensated by supplying holes via the ohmic gate structure, resulting in a stable threshold voltage (V
TH
). Meanwhile, a SiO
2
side wall is intentionally formed to achieve a moderate E-field at the island corner, and a JFET-like structure formed by the Schottky-metal/p-GaN junction delivers a self-limited gate leakage.