High-Performance AlGaN/GaN/Si Power MOSHEMTs With ZrO2 Gate Dielectric

We report on the power performance of GaN-on-Si metal–oxide–semiconductor high electron mobility transistors (MOSHEMTs) with a high-
${k}$
ZrO
₂
gate dielectric formed by atomic layer deposition. As a result of the high-quality ZrO
₂
and ZrO
₂
/AlGaN interface, the MOSHEMTs demonstrate an excellent ON/OFF current ratio of
$5 \times 10^{10}$
, a steep subthreshold slope of 66 mV/dec, a small hysteresis of ~0.05 V, and a high breakdown voltage of 1084 V at
$1~\mu \text{A}$
/mm. Effective suppression of current collapse with a dynamic-to-static ON-resistance ratio of 1.78 at a drain bias of 600 V is also achieved in the device. Benefiting from the highly uniform gate stack, large-area devices with a gate width of 20 mm were also demonstrated using the ZrO
₂
gate dielectric, exhibiting a maximum output current of 7.4 A, a low ON-resistance of
$0.66~\Omega $
, and a high breakdown voltage of 650 V at an OFF-state drain current of
$1~\mu \text{A}$
/mm.