Improved Drain Current Density of E-Mode AlGaN/GaN HEMT with Double-Doped P-Gate

A novel E-mode AlGaN/GaN HEMT with double-doped p-gate (DDP) is proposed to improve output current and verified by TCAD simulation. The heavily p-doped region of the AlGaN gate layer ensures enhancement-mode (E-mode) operation and the lightly p-doped region of the AlGaN gate layer reduces the channel resistance. The simulated results have demonstrated that DDP HEMT delivers a much larger maximum drain current (I
_MAX
= 334 mA/mm) than the conventional p-gate (CP) HEMT (I
_MAX
= 144 mA/mm) while maintaining a high threshold voltage (V
_TH
~1.5 V). The simulated results also indicate that the DDP gate structure could decrease the peak electric field (E
_C
) and thus improve the reliability of the device under off-state high-drain-bias (HDBT).